Sounds like a possible bad sector Dace - go to my computer, right click on the affected disc, open up the tools tab and schedule a disk check. Or open up a command prompt box (under accessories) and run chkdsk /f - this will check your disc and attempt to repair any errors etc. When you input that command, it should say it needs to be done when files are not in use, do you want to schedule for when your computer gets rebooted. Click on yes and restart your machine.
hope this helps,
Wurz