Windows 98: scanreg /restore after booting in MS-DOS and go back to yesterday.
The procedure for Windows XP to do a system restore from 'Save Mode with Command Prompt' (press f8 during the boot to go there) is described in http://support.microsoft.com/kb/304449
Hope this helps.
installed MS NET FRAMEWORK 1.1 AS UPDATE,MUST HAVE BEEN A BAD INSTALL AS NOW CAN'T REBOOT, IT wants me to wait for installation which never happens. It also won't let me uninstall it-what should I do?