If you are using WINXP double click on 'My Computer', right click on your 'C' drive and left click on 'Properties' on the pop-up menu, left click on the 'Tools' tab, in the 'Error-checking' section left click on the 'Check Now' box.
Tic both selections in the Check Disk options and then left click on the 'start' button.
Your computer will display a pop-up asking you to do this on next Reboot.
This is what you want.
Then Reboot your computer.
Leave your computer alone and let it do it's thing.
This can take quite a while so be prepared for a long wait.
It does 5 different scans.
I hope this helps you.
Tsel
