Well well…
What is exactly happening? Can you access all options but not the residents settings (the first line), start avast, open log viewer and change program settings and even stop providers?
Well, avast is very bad installed :cry:

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?