The old ScanDisk, which appeared in all previous consumer versions of Windows, disappeared in XP. Instead, we got Check Disk, which Microsoft considers an improvement.
Diligent users who ran ScanDisk as a scheduled task are out of luck with XP. Check Disk needs a file that Windows uses, and has to run before Windows boots.
So do it this way: Click Start>>My Computer. Right click the hard drive (probably C

. Click Properties and select the Tools tab. Click Check Now. Check the two boxes and click Start. In the ensuing message, click Yes.
Restart the computer. And you're good to go!