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Do Not Delete Unknown Files

If you are not sure what a file does, do not delete it.

If you are deleting files from you computer in order to free some space, make sure you know how the files are used and that you are certain that you do not need them.

The following is a list of tips to help you remove safely files from Windows machines and Macintosh machines:

Windows 2000, XP, or Vista:

1. Do not remove any files or folders under the \Windows or \Winnt directory. These are the default system folder names in Windows (unless you chose to change the names of those directories when you installed Windows). These folders contain system files that Windows needs to run.
   • You can identify system files by the file extension, which is composed of a dot (".") and three letters that follow the name of the file. Usually Windows is configured to hide file extensions, but you can configure Windows to display file extensions. Once that is done, you can see the file extensions of the system files, which include:
     • .ini
     • .dll
     • .sys
     • .com
     • .log
     • .bat
     • .exe
     • .cab
   • If you encounter a file with a file extension you don't recognize or understand, try entering the file extension in a web search engine and see if you can find information about it.
2. Do not manually change or delete any boot or configuration files (unless explicitly instructed to do so). These files include:
   • autoexec.bat
   • config.sys
   • win.com
   • msdos.sys
   • win.ini
   • system.ini
   • user.dat
   • system.dat
   • boot.ini
   • ntldr
   • ntdetect.com
3. If you want to delete a program you installed, first look to see if there is an Uninstall icon or file for that program. If there is, use that uninstaller to remove the software. If the program does not come with its own uninstaller, use the built in Add / Remove Programs feature of Windows to remove the software.
   • Click on the Start button.
   • Choose Settings from the menu that appears.
   • Choose Control Panel.
   • Double-click on the Add / Remove Programs icon.
   • Find the program you want to delete in the list of programs. Remove it.

   Note: If the program is not listed, and it did not come with its own uninstall program, only then should you try to remove the program by manually deleting its files and directories.

4. If you need to free some space but don't have any programs you want to delete, try emptying the Recycle Bin. You might also want to try clearing the cache (an area where web pages you recently visited are stored temporarily) of Firefox and/or Internet Explorer (you can choose Help from the menu of Firefox and/or Internet Explorer to learn how to do this).

Macintosh

1. Don't delete files or folders from the System Directory.
2. If you want to remove an application, drag the application folder to the Trash and empty the Trash. Be sure that you don't have any personal files saved in that folder.

Linux/UNIX

1. Don't delete files or folders in the root directory "/"
2. Dotfiles are configuration files used to configure settings for programs, startup, and your environment
3. If you are not really sure what a file or folder is used for, your best bet is not to remove or modify it
4. There is an enormous amount of information on the web when it comes to Linux/Unix files or types of files so if you want to know more about a file or folder you should probably start by using your favorite Internet search engine to find more information about the file or folder in question. The web site Unix: What Are All These Dotfiles In My Glue / WAM Account For? has information about dotfiles on the Office of Information Technology WAM/Glue UNIX system which is usually the same on other UNIX platforms but may or may not be the same for other Linux/UNIX platforms