The problem is that xp will not let you fix errors while it is running. So when you check for errors you have the box for fix errors checked it will not fix them, instead it will ask you if you want it to schedule check dsk on reboot. You select yes and during reboot it will scan and fix errors. Now, if you just want to see if there are any errors without rebooting you uncheck fix errors and it will scan and tell you if there are any errors. If so you have to check fix errors box scan again, select yes on schedule scan dsk on reboot, and reboot. After this you can defrag. I have found with xp that errors are not as common as with 98 se and the fat 32 format. I usually only get them with a bad shut down. Hope this helps. ikester