Restore earlier date
Microsoft Windows comes with a System Restore function. If, of course, Windows was erased completely, this feature no longer works. However, if your computer is acting up, but still functions in a basic way, you can restore it. After the BIOS message but before the Windows logo, hit the F8 key on your keyboard repeatedly. This will cause Windows to boot into Safe Mode. On Windows XP, System Restore is at Start Menu => Accessories => System Tools => System Restore. I'm not sure if it's location has changed much in newer versions of Windows, but you can still use the search feature of the newer start menus to locate it. Once you're there, just follow the instructions and hit next.Note: System Restore does not accept arbitrary dates, it must restore to a previously-defined Restore Point. These are created periodically, such as immediately before software is installed.