[Brad]

This thread serves the purpose of providing answers to Frequently Asked Questions to our membership.

If your Mac acts strangely or you are generally experiencing problems with it, please check this FAQ page for possible solutions. It'll save us all some time and trouble if you read this page first *before* posting your questions to new Genius Bar threads.

Here is a list of current subjects covered here:

• Where's my drive space?!?
• Repairing permissions
• Repairing your Hard Drive
• Clearing the Caches
• Resetting or "Zapping" the PRAM
• Turning on the Safari Debug Menu
• Run cron scripts via Terminal for maintenance
• Open Firmware & Resetting NVRAM
• Resetting Your Password
• Booting from a CD/DVD
• Moving your Home folder
• Optimizing Cached Safari Files
• Move your swap files to another partition
• Reinstalling printer drivers without reinstalling the entire system
• Rebuilding the Launch Services
• Joining an encrypted AirPort wireless network from a Windows PC
• Safe Boot
• Uninstalling Applications
• How to play .avi, DIVX, and other movie files
• Keyboard Shortcuts Description
• Wiping your computer for resale
• Updating/redoing Application Prebinding
• Copying your music off of your iPod and putting it back into iTunes
• Killing an Unresponsive Application
• How do I test my network connection?
• External Hard Drives

Terms of use:

• This thread is only for FAQs.
  ...such as 'How can I reset the PRAM?'
• Only post here if you have something to add.
  Add topics we haven't covered yet, nothing else.
• If you post, format your submitted text.
  Use the style of the posts before yours.
• Post only one explanation at a time.
  This keeps the FAQ tidy and easy to search and read.

"Basic Troubleshooting" should consist of following the steps below first. Please make sure you've tried all these before starting a thread seeking help for general stability, startup, or performance issues. Details for each procedure listed can be found below.

1. Repairing permissions
2. Repairing your Hard Drive
3. Clearing the Caches
4. Resetting or "Zapping" the PRAM
5. Open Firmware & Resetting NVRAM
6. Rebuilding the Launch Services
7. Updating/redoing Application Prebinding
8. Safe Boot

Please do not post in this thread unless you are explaining a new troubleshooting technique.

[alcimedes]

Where's my drive space?!?

If you bought a large HD, and are only seeing approximately 128GB of that space, here's the deal.

Older computers can't address drive space over 128GB, so that big drive you bought is capped at 128GB instead.

An external Firewire drive case that's designed to support drives over 128GB will work, as long as you're the latest version of OSX.

[hyperb0le]

Repairing permissions:

If your computer begins to act strangely, the first thing you should do is repair your permissions. You should also repair your permissions on a regular basis, particularly after software updates or installs, even if nothing seems wrong.

Open Disk Utility (/Applications/Utilities/Disk Utility.app), select your hard-drive, switch to the 'First Aid' tab and press "Repair Disk Permissions."

[Brad]

Repairing your Hard Drive:

In addition to repairing permissions, you should also attempt to repair the hard drive's filesystem if you experience crashes or other odd bugs.

You can repair non-system drives in the Disk Utility (/Applications/Utilities/Disk Utility.app) program. Select your hard drive, switch to the "First Aid" tab, and press the "Repair Disk" button.

To repair your primary "bootable" system hard drive, you must boot into single-user mode (hold the apple and 's' keys while rebooting). At the command prompt, enter the command:

/sbin/fsck -fy

This will force FSCK (FileSystem ChecK) to run and automatically repair any errors it encounters. When completed, if you see the message that your filesystem was modified, run the command again. Repeat until you receive a message that says your volume "appears to be OK." When complete, enter the command:

reboot

As an alternative to using the commands in single-user mode (ie. for the terminal-phobic), you can reboot from your Mac OS X Install CD/DVD and choose Disk Utility from the Installer menu. Then, you can use the earlier instructions to repair any hard drive including your system's boot drive.

[Brad]

Clearing the Caches:

If programs appear to be retaining old or incorrect data (Finder icons are wrong, System Preferences has wrong or duplicate items) or, again, if applications are just generally behaving strangely, you should delete your caches. Is is completely safe to remove the files stored in cache because, as the name implies, they are only cached copies of data that are stored for quicker access. They will be regenerated as needed.

You should close all running programs before clearing the caches. This will minimize the chance of problems arising if an application is expecting and tries to access the cache. You should then restart your computer (or at least log out and log back in) after deleting the caches so the Finder and other system services will be refreshed.

To clear the caches, delete the folder named "Caches" in your home's Library folder. If you are the administrator of your Mac, also delete the "Caches" folder from the top-level Library folder.

[Brad]

Resetting or "Zapping" the PRAM:

PRAM (Parameter RAM) stores a number of system-wide settings that are needed when the system first loads and before it can access the hard drive. Sometimes these settings may become corrupted and the PRAM needs to be "zapped" or reset. If you are experiencing problems with your Mac retaining any of the following settings, you should reset your PRAM:

• Speaker volume
• Time zone location
• Key repeat delay and rate
• Mouse speed and double-click rate
• Monitor depth and resolution
• Default startup disk
• Startup options (verbose mode, single-user mode)

To reset the PRAM, reboot your Mac while holding the apple, option, 'p', and 'r' keys. Keep holding these keys after the first chime until the computer resets and chimes a second time. Then, you may release the keys and the computer will boot normally.

You can safely reset the PRAM as frequently as you like. Many people include this as a step when they perform routine repairs and checks such as the permissions and hard drive repairs.

[curiousuburb]

Turning on the Safari Debug Menu

To do so, open Terminal, and type the following on one line (or copy and paste), then hit <enter>:

defaults write com.apple.safari IncludeDebugMenu 1

Restart Safari.
A new menu titled "Debug" will appear on the right of the help menu.

The Debug Menu primarily offers information, but there are settings to control cache, some bookmark import tools, and User Agent settings which allow Safari to spoof websites into thinking it is actually Netscape/Mozilla/MacIE/WinIE/etc

to remove the Debug menu, use the above terminal command but replace the 1 with 0 (zero)

[VOX BARBARA]

Run cron scripts via Terminal for maintenance

there are 3 different ones:
1. "daily" --> removing old log files
2. "weekly" --> rebuild locate database
3. "monthly" --> rotating log files

How to:
open terminal-->type in: "sudo periodic daily"-->hit enter, done
same with other tasks

you can run all 3 tasks all at once by typing:
--> "sudo periodic daily weekly monthly"

all typings without quotes ("")!!!

[FFL]

Open Firmware & Resetting NVRAM
(similar but not exactly the same as resetting PRAM)

Note: the Intel-based Macs do not use Open Firmware. The following instructions only work for PowerPC-based Macs (G3, G4, G5).

Boot computer into Open Firmware by holding down Option-Command-o-f keys (o and f for open firmware) immediately after powering computer up.

At the Open Firmware prompt, type:
reset-nvram
Press Return.

Next, type:
reset-all
Press Return.
Some text will display and computer will restart.


Other useful Open Firmware commands include:
shut-down
mac-boot
eject cd

[Ryan]

Resetting Your Password: by CubeDude

If you need to reset your password for whatever reason, you need the Mac OS X install CD(only the first one) or the Software Restore CD(or DVD) that came with your Mac.

1. Boot off of the Install* CD. To do this, insert the CD, and shut down. Then hold down the C key and power up. Or, if you are using the retail install CD, you can insert the CD, while the computer is running, and double-click on the "Install Mac OS X" icon.

2. Click on the Installer menu. Open the installer menu. It's next to the Apple logo in the top-left corner. It's also known as the Application menu.

3. Click on Reset Password. Follow the instructions in the resulting window.

4. Reboot to your hard drive.

You do NOT need to reinstall.

*These same directions apply to the Software Restore CD.

[Ryan]

Booting from a CD/DVD: by Cubedude

Sometimes you need to boot off of a CD to fix ceartin problems.

1. Insert the CD.

2. Reboot holding down the C key until you see the start-up progress bar.

This applies in both Mac OS 9 and X.

[Ryan]

Moving your Home folder: by CubeDude

Sometimes its useful to keep your Home folder on its own hard drive, seperate from the System folder.

1. Open Netinfo Manager. It's located in /Applications/Utilities.

2. Authinticate yourself. To do this click on the Security menu and then on Authinticate... Enter your password.

3. In the center column, click on "users". Then find your user name in the right-hand column.

4. In the box underneath the three columns, find the "home" property.

5. Highlight that property/value.

6. After it is highlighted, double click on the value. Make sure you double-click on the value, or you could ruin your user. This should allow you to edit the value.

7. Type in the path to your new home folder.

It should look something like this:

/Volumes/VOLUMENAME/Users/USERNAME

Obviously, you should replace VOLUMENAME and USERNAME with their respective values.

8. Move over all the contents of the old folder.

Schvoo adds: Note that this can have adverse affects when running certain non-cocoa applications, especially installers such as InstallerVISE. I've been there, done that, and in the end I wound up moving my home folder back to where it belongs.

[Paul]

Optimizing Cached Safari Files (if Safari has gotten really slow): by Paul

Safari stores its cache in a folder in your library at ~/Library/Safari/ . Inside this folder should be four files and one folder.

The Bookmarks.plist file is where your bookmarks are stored and should be backed up.

The Downloads.plist file is where a history of your recent downloads is stored. You can easily purge this file by using the "clear" button in the downloads window of Safari.

The Form Values file is where autofill values are stored. This file can get very large after filling out a lot of forms online and can lead to slowdowns when selecting forms on webpages. This file can be periodically trimmed by going to the autofill prefpane within safari and editing "Usernames and passwords" or "Other forms". The former is listed by the webpage and user name while the latter is grouped by domain. Be sure to only delete items that you are sure you will not need.

The History.plist file is where your browsing history is kept. This file can easily be purged by using the clear history command in the history menu.

The Icons folder is where a cache of every website favicon (the little picture at the beginning of a web address) that you have ever loaded on your computer. This folder gets extremely large and can cause slowdowns while browsing. It is recommended to try and keep this folder under control as it can easily balloon to thousands of files and 10-20 megs in size (each file is tiny, a few k). One option would be to periodically delete the folder (just move it to the trash). But a better one is to delete all of the subfolders and then make the Icons folder read only.

To do this open the empty folder in the finder and "GetInfo" on it (command-I) and go to the "Details:" tab in "Ownership & Permissions:"
click the lock to authenticate and change the Owner's Access to "Read only". From now on this folder should stay empty and you shouldn't have to worry about keeping it clean.

This is only a temporary fix and could be modified in future updates of Safari but as of 10.3.4 this tweak will work perfectly.

[Schvoo]

Move your swap files to another partition: by Schvoo
Speeds up system performance by preventing disk fragmentation.

Moving your swap files (Thats g33k for "Virtual Memory" files) will prevent fragmentation on your main HD and speed things up a lot, and instead of me explaining how to do it, ill just direct you to this awesome link: link

[Ryan]

Reinstalling printer drivers without reinstalling the entire system: by CubeDude

First, check the cables(thank you, FFL).

If your printer is no longer working well, it could be a bad driver. This can be easily fixed with the OSX install CD.

If you have an older Epson printer, insert the third disk. The Epson drivers had to be split into two seperate packages, and the first half is on the second disk, while the rest on on the third.

If you have any other printer, insert the second disk.

On the CD, open a folder called "Packages". Look for a .pkg file with your printer manufacturer's name in it, such as "EpsonPrinterDrivers.pkg". Open this file, and follow the instructions that appear on screen.

If you aren't sure which disk your Epson printer might fall under, simply install both of them.

[Brad]

Rebuilding the Launch Services:

If the "Open With" menu in the Finder shows applications that are no longer installed or shows duplicate entries, you can use the following Terminal command to rebuild your LaunchServices database. Note that this command should be entered all at once.

/System/Library/Frameworks/ApplicationServices.framework/\
Frameworks/LaunchServices.framework/Support/lsregister \
-kill -r -domain local -domain system -domain user

Note: for systems running 10.6 or higher, instead of the above command you should run:

/System/Library/Frameworks/CoreServices.framework/\
Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister \
-kill -r -domain local -domain system -domain user

After this execution completes, you should reboot or at least log out and log back in to force the Finder and other applications to refresh. Simply quitting and relaunching them may not have the desired effect.

On older systems before Mac OS X 10.3, instead locate and delete any files in ~/Library/Preferences whose names begin with "LS".

[Brad]

Joining an encrypted AirPort wireless network from a Windows PC:

Apple's Airport Base Stations have unique feature of creating an 128-bit encryption based on string you specify as a password. It can be an plain text string like "applenova".

Windows based computers usually require 13 ASCII characters or 26 hex characters string to access 128-bit encrypted networks.

• Launch AirPort Admin Utility (located in /Applications/Utilities), and select your Base Station.
• Click on configure button, and enter your password.
• Now click on Password icon.
• Write down the hex equivalent of your password. If your password is exactly 13 characters long you will be provided with ASCII string as well, otherwise only hex value will be shown.
• Use this hex password to authenticate from your Windows computer.

[Brad]

Safe Boot:

To load Mac OS X via "Safe Boot", hold shift as the system reboots. A message should appear in the progress window indicating the alternate booting mode. This does several things:

• It forces a filesystem check of the startup volume.
• It loads only required kernel extensions (some of the items in /System/Library/Extensions).
• It runs only Apple-installed startup items (some of the items in /Library/StartupItems and /System/Library/StartupItems - and different than login items).

If you hold the shift key while logging in, it will disable all of your user's login items.

[Brad]

Uninstalling Applications:

In an overwhelming majority of cases, applications for Mac OS X can be installed and uninstalled by the "drag and drop" procedure. The latter consists of simply dragging the application itself (or its parent folder) to the Trash. Yes, it's really that easy!

You can also remove support files and settings files for the application located in the top-level Library folder and your home Library folder, but this is not necessary. Those files only store preferences and support files for the applications and will remain completely inert when the application is not running.

There is also nothing directly analogous to the Windows registry in Mac OS X that needs to be edited to make or break applications.

See Uninstalling Mac OS X Apps for more details.

[MCQ]

How to play .avi, DIVX, and other movie files. AKA: Quicktime can't understand this file: by MCQ

There are a couple options available:

• Use a third party player such as VLC or MPlayer
  
• Download the 3ivx codec for OS X for use with Quicktime: 3ivx codec - OS X
  
• Download the DivX codec for OS X for use with Quicktime: DivX codec - OS X

[Brad]

Keyboard Shortcuts Description:

• The cloverleaf (campground) symbol is the shortcut for the command key.
• The hollow up arrow is the shortcut for the shift key.
• The carat (^) is the shortcut for the control key.
• The "split path" is the shortcut for the option key.

The UP arrow is used for shift because shift usually makes something UPPER case. The "split path" as I called it is used for the alt/option key because it looks like a symbol you'd see for taking an alternatate/optional route on a trail. The carat has always been the control symbol in Unix and Linux command lines over the years.

[sunrain]

Wiping your computer for resale by sunrain

This is for folks that are selling their old computer and want to have their data safe from harvesting and at the same time make the computer ready for its new owner. After making extra sure you've got any data you want off of the computer, there are really two main steps.

• Format the hard drive (various options)
• Re-install the operating system

1. Format the hard drive:

Your most basic method of formatting the hard drive is to use your install discs and select the Erase and Install option and skip down to the 're-install' step. If you're not the slightest bit worried about your data, or don't care, this is your easy option.

The next formatting options are a bit more involved and easiest* done with two computers; both with Firewire ports. These options provide much more security from data harvesting. You'll be using one computer (the controlling computer) to wipe the hard drive of the other (target computer) using 'Target Disk Mode." This mode basically turns the computer into a large hard drive and is accessible like any external drive.

Restart the 'target' computer you want to reformat and press 'T' during startup to enter into this mode. You'll know when it has worked when you see a Firewire symbol on the screen. Make sure your 'controlling' computer is booted up. Plug the Firewire cable into this computer first and then into the 'target' computer. The 'target' computer should then mount as a hard drive on the desktop of the 'controlling' computer.

*Note: You can also use your Disk Utility from your install disc(s).

Open a Finder window on the 'controlling' computer and select Applications>Utilities and open Disk Utility.

Disk Utility lists all the available drives and volumes in a column, on the left-hand side of the window. The drives usually have cryptic names (like "ST380020A") while your volumes are indented and reflect the names you are familiar with and you see in the Finder's Computer window. You should see the mounted 'target' computer drive and volume(s) in the utility along with the 'controlling' computer's hard drive (and volume(s)).

Select the 'target' computer drive and then select the Erase tab and then the Security Options button. The Security Options button allows you to select a hard drive "scrubbing" method that will make your previous data harder to retrieve from your disk. To make it more difficult to recover the files on the disk, you have the option of doing this once, seven times, or 35 times. If you have a large disk, overwriting the free space several times can take a very long time. Select your option, close the Security Options dialog and select erase.

Take a walk, watch a movie and wait for it to finish. Then unmount the 'target' computer from the 'controller' computer and remove the Firewire cable.

Brad's wisdom on the subject:

Simple reformatting (Erase and Install) is enough for the casual user. Zero-wiping is good for any educated user. Multiple-pass-wiping is only for the truly paranoid.

2. Re-install the operating system

This is as straightforward as any other Erase and Install, with a slight change towards the end. When the installation process informs you that the installation is finished and will reboot, allow the computer to start the reboot process and then power it off before it reboots (i.e. once you hear the boot sound). This allows you to install the operating system so that the opening 'welcome' movie will come up when the new owner first boots. This allows the new user to create their own account, put in their own preferences, register, etc.

[Brad]

Updating/redoing Application Prebinding:

These procedures are generally unnecessary under 10.2 and higher. Applications automatically check their prebinding upon launch and update themselves automatically. Also, some installers will force an update of application prebindings during the "optimizing" phase at the end. This is actually redundant since applications, as mentioned, update it automatically. Hence, you should never have to intervene. You can find more details in Prebinding Explained, by Bill Bumgarner.

However, should a case arise where the update mechanism fails and applications refuse to launch, you can try these commands in the Terminal to manually run a system-wide update of the prebindings.

To "update" the prebindings, checking and changing only the ones that appear to be out of date, run the following command:

sudo update_prebinding -root /

To force the rebuild of all of the prebindings even if they appear to be up to date, run the following command:

sudo update_prebinding -root / -force

You will be asked for your administrator's password to execute either of these. You should wait until they are complete before launching any new applications. To be sure it has affected currently-running processes as well, you should also reboot your computer immediately after running either of these commands.

[faramirtook]

Copying your music off of your iPod and putting it back into iTunes.

Oh noes! You lost all of your music somehow, but it's all still on your iPod, but you don't know what to do!

Well, all of your iPod's internal workings are inside a hidden folder called "iPod_Control". Inside that folder is a bunch folders. One of them is called "Music", and inside there is your music, contained in a bunch of cryptic-looking folders with an F and two numbers.

Now, you could get a tool like TinkerTool, enable hidden folders, and drag the "Music" folder to your desktop to get it back. Or, you could just paste a line of text into the Terminal, and all would be well.

So, fire up a terminal, paste this text into the terminal, replacing "iPod Name Inside Quotes" with your iPod name, inside quotes.

mkdir ~/Desktop/Music; cp -R /Volumes/"iPod Name Inside Quotes"/iPod_Control/Music ~/Desktop/Music

So, if your iPod's name was Susan B. Anthony, you'd have /Volumes/"Susan B. Anthony"/iPod_Control/Music.


Now, to get the music back into iTunes, just open iTunes and drop the folder onto your library. Ding!

[Gargoyle]

How do I test my network connection?

This is not specifically a common question, but is the starting point to finding the problem and solution for a lot of network related issues. It consists of 3 basic steps which I would normally do in terminal, but for the sake of this FAQ I'm going to use the GUI tools.

Step 1 - Testing your core network software

• Launch "Network Utility" from Applications/Utilities.
• Select the "Ping" tab from the top.
• In the first text box (Network Address) enter "127.0.0.1"
• Make sure that the "Send only 10 pings" option is chosen.
• Click the "Ping" button to the right.

You should see results like this...

Ping has started ...PING 127.0.0.1 (127.0.0.1): 56 data bytes64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.101 ms64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.098 ms64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.092 ms64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.094 ms64 bytes from 127.0.0.1: icmp_seq=4 ttl=64 time=0.089 ms64 bytes from 127.0.0.1: icmp_seq=5 ttl=64 time=0.094 ms64 bytes from 127.0.0.1: icmp_seq=6 ttl=64 time=0.091 ms64 bytes from 127.0.0.1: icmp_seq=7 ttl=64 time=0.092 ms64 bytes from 127.0.0.1: icmp_seq=8 ttl=64 time=0.117 ms64 bytes from 127.0.0.1: icmp_seq=9 ttl=64 time=0.090 ms--- 127.0.0.1 ping statistics ---10 packets transmitted, 10 packets received, 0% packet lossround-trip min/avg/max/stddev = 0.089/0.096/0.117/0.008 ms

This test uses a special IP address to test your TCP/IP software. If you get errors at this point then you need to resolve them before you go any further.

Step 2 - Testing your cable / wireless connection
90% of the time, your computer will be on a local area network (LAN) and there will be some sort of router between you and the rest of the internet. For the rest of this test I am going to assume your computer is connected to an ADSL router and that the router is set to give out network information using DHCP.

• Open "System Preferences" and choose "Network".
• From the "Show" drop-down menu, select "Network Status".
• Select the connection you're testing and choose "Configure".
• Choose the TCP/IP tab from the top.
• Verify that "Using DHCP" is selected from the "Configure IPv4" option. If not, select it and click "Apply Now" from the bottom right corner.
• Make a note of the number shown next to "Router".
• Return to the status screen by choosing "Network Status" from the "Show" drop-down menu.
• The coloured dot next to the connection you are testing should be green.

If the dot is not green then you have a problem with your physical connection or router/modem settings. If the dot is green, continue...

• Switch back to the "Network Utility" and the "Ping" tab.
• Replace the 127.0.0.1 address with the number you took note of from the previous section.
• Click "Ping".

You should see almost identical results to the first test. If you get errors here then your computer cannot talk to your router. Recheck all your settings using the instructions that came with the router.

Step 3 - Testing the 'net
While still in the "Network Utility" programs "Ping" tab, replace your "Router" IP address from the previous step with "www.google.com" and click "Ping". Once again you should see the same type of results from the previous step. Alternatively, you could just try to access a website. However, you must make sure you do not load a cached page. The easiest way to do this is to go to google and search for a random string.

If you get an error that states "Unable to resolve" or "Unknown host" or if the Ping appears to do nothing for a long period, then you have an internet connection problem.

If you have passed all these tests and still can't connect to XYZ...
Then ether the fault is with the destination server, or your firewall settings. Ask in Genius Bar, and give as much information as possible, including that you have completed the "Network Test" in the FAQ's.

Hope this helps!

[FFL]

External Hard Drives

The best and most reliable options for any external hard drive are the following:

FORMAT - Mac Os Extended (Journaled) which is also known as HFS+.

Most hard drives you purchase will be preformatted in a PC format such as FAT or NTFS.

It's also not a bad idea to zero the data on the drive when formatting, which will map out any bad sectors.

CONNECTON - Use FireWire. Don't use USB. FireWire is both faster and more reliable.

[Brad]

Killing an Unresponsive Application

If an application has frozen or stopped responding to input, the last resort method of terminating it is colloquially called "force quitting" it. You should only force an application to quit if you have no other options. Terminating an application in this way will cause you to lose all data that the application is processing and may cause open files to be corrupted.

There are four common methods in Mac OS X to "Force Quit" an application that has stopped responding. These include:

1. cmd-opt-esc: Pressing the keystroke combination of command (Apple), option, and escape should cause the "Force Quit Applications" window to appear. This window can also be accessed from the Apple menu in any application that is still responsive. If an application does not immediately respond to cmd-opt-esc, you may hold cmd-opt-shift-esc for several seconds to terminate the frontmost application.
2. Dock icon's Force Quit: Holding the control key and clicking or right-clicking an application's Dock icon will present a menu of functions including the standard "Quit" item. Hold also the option key to change the "Quit" item to "Force Quit".
3. Activity Monitor's "Quit Process": Launch the "Activity Monitor" application from the /Applications/Utilities folder and you will see a list of all running applications and processes on your computer. Choose a process name from the list and choose "Quit Process" from the View menu. Then click "Force Quit" in the sheet that appears.
4. The "kill" command: Launch the "Terminal" application from the /Applications/Utilities folder. Alternatively, externally connect to the machine using an SSH or terminal account. At the command-line interface, enter the command "ps uxc". A multi-column output of text will appear that describes the currently active process owned by your username. The second column, named PID, should contain a unique number for each process. Find the process you want to quit and run the command "kill -9 NUMBER" where NUMBER is the number you found. For example, "kill -9 11223" would terminate the process with PID 11223.