I got a message to run chkdsk b/c of a corrupt file in Avast. I then decided to run Avast and got this message:
Unknown Error
Skin is not complete. Look at the following description: Skin is not loaded properly. It then lists several "Skin image with name “**” is not loaded. It lists this 30 times with a different “name” each time.
Which is your Windows? 98, Me, XP, Vista?
Do you use any other antivirus in your computer?
Can you try to repair your installation?
Go to Control Panel > Add/Remove programs > avast! antivirus > Remove. Then choose Repair function in the popup window (Repair).
If this does not help, can you uninstall / boot / install / boot again?