Whoa. I just went through this myself.
It would help if we knew what kind of computer you have, and what version of Windows.
ScanDisk won’t scan the disk if it’s moving, which means if something like a screensaver or an automatic Internet stock exchange update or AOL Instant Messenger kicks in.
Try starting the computer in Safe Mode–for Win95 it’s pressing F8 when you see the words “now starting Windows 95” when you turn the computer on. Safe Mode turns off all the automatic programs like those.
ScanDisk attempting to start 10 times and then starting over says to me you’ve got something automatic writing to the disk halfway through.
Is your computer locking up and giving you the blue screen while you’re attempting Defrag or ScanDisk? Or is it at other times? 'Cause if it’s at other times, then it’s two separate problems.
No, you don’t need a new hard drive. This is fixable. If nothing else, you can always reinstall your Windows program, or if worst comes to worst, do something called Re-formatting your hard Drive. Your Windows CD, when you put it in the CD-ROM, and it Auto-Runs, ought to come up with a menu that mentions this.
Reformatting your hard drive is a Last Resort. You’ll lose EVERYTHING that’s stored on there, Internet Favorites, e-mail, word processing, the works. You have to make a whole boxful of backup disks beforehand. Very tedious.