The repair console will ask which partition you wish to log into. (DO NOT use the number pad to choose the partition number or press the <ENTER> key as the system will reboot at this point.) It asks in case there are more than one instance of Windows Xp or 2000. Next you will required to enter the administrator’s password. Press <ENTER> to signify the default of no password if you haven’t established one.
Once you are logged in you’ll be told to enter ‘help’ for a list of commands. If you have received the message “cannot find ntldr”, you may need to repair the master boot record with the command ‘fixboot’. It is also possible to rebuild the master boot record (in case of a boot sector virus) with the command ‘fixmbr’. You’ll want to run ‘fixboot’ afterwards and before you exit the repair console. Like Dos, you exit with the command ‘exit’.
Update for Vista and Windows 7:
Repeatedly type the function key F8 at startup for a list of ways to start Vista or Windows 7. The first best choice to make, like in Xp, is “Last Known Good Configuration”. If your system won’t even go to “Safe Mode With Command Prompt”, pick “Repair My Computer” at the top of the list. From here you will find a variety of tools including, on some systems from the major manufacturers, the option to revert to day 1 just like it came out of the box. Be advised however that you could lose any stored documents, pictures, music, etc. Unlike Xp and Millenium it is possible to launch System Restore without booting the operating system. Thanks Microsoft; this was definitely an improvement!
Booting the Vista or Windows 7 disk will offer a variety of ways to fix your operating system. System Restore is available from here also, but it may be helpful to open a command prompt. The command HELP will display commands that can be used here. Not all Dos commands will work. For repair of the master boot record, the command is BOOTREC.EXE /FIXMBR and you may want to follow that with BOOTREC.EXE /FIXBOOT.
