I Cannot do A Virus Scan

I have avast 4.8 home edition. I need help. When I click on the start avast antivirus the screen comes up and it starts testing the memory and startup files but then this error message comes up from avast.

Unknown error:
skin is not complete. Look at the following description:

Skin is not loaded properly.

The Simple user interface does not appear

Do I need to reinstall Avast?

Will this work http://forums.spybot.info/blog.php?b=24

Thank you this helped alot ;D

i will send you the bill ;D