Where can i Download Avast version 5??
Filehippo.com keeps old versions of software under avast it will have the current and previous versions.
That said what was the problem with avast 6.0.1000 ?
Would it not be bets to try and resolve any problem as it really is a better option.
My mom sendet me a License file for Avast 5
That same lisc file will work on version 6. Enjoy 
As Bob says this license should be good for avast 6 if it is still in date.
I bet your glad that you asked in the forums ;D
www.avast.com
There are two versions: antivirus pro and the suite (avast Internet Security) that is an antivirus + firewall.