To know how to post a screenshot, see http://forum.avast.com/index.php?topic=8982.0
You can use Gadwin PrintScreen to get a screenshot (http://www.gadwin.com/printscreen/) or the free version of WinSnap 1.1.10 (http://www.filehippo.com/download_winsnap/?2173).

Wow… 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). You must be connected to the internet while repairing.
If this does not help, can you uninstall / boot / install / boot again?