Originally posted by Polymorphic
often the easiest way to run scandisk is to pop into safe mode.
Usually programs running in the background will cause the file system to change - which makes defrag (and scandisk) startover.
Best way is to go into Safe Mode (just tap the F8 key during POST upto when windows starts). None of that stuff in MSCONFIG will run or start in safe mode - hence no programs running in the background. When you're done defraging - run scan disk or those anti-virus scans, things go a bit faster in safemode
And a good hint, if you're using a free spyware/adware program like Spybot - Search & Destroy, or Adaware SE 6, run those in Safe Mode - 99% of the time it will be able to get rid of the spyware/adware programs without a restart!