CONFIG.SYS Commands The CONFIG.SYS file is a text file that contains special commands. These commands configure your computer's hardware components so that MS-DOS and applications can use them. When MS-DOS starts, it carries out the commands in the CONFIG.SYS file. Typically, the CONFIG.SYS file is located in the root directory of drive C. CONFIG.SYS commands The following CONFIG.SYS commands can be used only in the CONFIG.SYS file: The following commands are commonly used in the CONFIG.SYS file and can also be typed at the command prompt: The following special CONFIG.SYS commands are used only to define multiple configurations within the CONFIG.SYS file: For more information about defining multiple configurations, see . Special characters in the CONFIG.SYS file The CONFIG.SYS file can also contain the following special characters: ; Specifies that the current line is a descriptive comment and should not be carried out. Insert this character at the beginning of the line. (You can also insert a comment by using the REM command.) ? Specifies that MS-DOS is to ask for confirmation before carrying out the current command. Insert this character immediately after the command you want to prompt for, without any intervening spaces, but before the equal sign (=). For example, to have MS-DOS ask for confirmation before carrying out the DOS=HIGH command, you would change the command to read DOS?=HIGH. To have MS-DOS ask for confirmation before carrying out the DEVICEHIGH /L:1,7280=MYFILE.SYS command, you would change the command to read as follows: DEVICEHIGH? /L:1,7280=MYFILE.SYS Bypassing CONFIG.SYS and AUTOEXEC.BAT commands If you are having system problems that you suspect are caused by one or more commands in your CONFIG.SYS or AUTOEXEC.BAT file, you might want to bypass some or all the commands in these files. (For information about bypassing DriveSpace, see the next section.) To bypass all the commands in your CONFIG.SYS and AUTOEXEC.BAT files, press the F5 key immediately after starting your computer, when you see the text "Starting MS-DOS...". To bypass individual CONFIG.SYS and AUTOEXEC.BAT commands, press the F8 key instead. MS-DOS will then prompt you to carry out or bypass each command. To carry out all remaining startup commands, press ESC. To bypass all remaining startup commands, press F5. To disable this feature, add the command to your CONFIG.SYS file. Starting your computer without loading DRVSPACE.BIN DRVSPACE.BIN is the part of MS-DOS that provides access to DriveSpace compressed drives. Normally, if your hard drive has been compressed using DriveSpace, DRVSPACE.BIN is loaded even if you press F5 or F8. There are two ways to disable this: To start your computer without loading DRVSPACE.BIN, and to bypass all the commands in your CONFIG.SYS and AUTOEXEC.BAT files, press CTRL+F5. To start your computer without loading DRVSPACE.BIN, and to bypass individual commands in your CONFIG.SYS & AUTOEXEC.BAT files, press CTRL+F8. MS-DOS will then prompt you to carry out or bypass each CONFIG.SYS and AUTOEXEC.BAT command. To carry out all remaining startup commands, press ESC. To bypass all remaining startup commands, press F5. Note: If you bypass DRVSPACE.BIN, you will not be able to gain access to your DriveSpace compressed drives until you restart your computer with DRVSPACE.BIN. (Your compressed drives will remain on your hard disk as hidden files with names such as DRVSPACE.000. Do not delete or rename such files.) To disable this feature, use the command. For more information about your CONFIG.SYS file, see the chapter "Configuring Your System" in the MS-DOS User's Guide.