Intended For Windows XP Windows 2000 Windows Me Windows 98 Windows 95

Run Scandisk (scandskw.exe in Windows 95/98/Me, or chkdsk.exe in Windows 2000/XP) whenever you suspect a problem.

This includes if the system crashes whenever you try to perform a particular action, and if a particular program or driver refuses to load. It's also good practice to run Scandisk and the Disk Defragmenter (Windows 95/98/Me only) after a serious crash of any kind, as well as on a regular basis (such as at the end of the week).