What version of avast are you using? Free? Pro? AIS?
Dell Inspiron, Win7x64 SP1, Pentium Dual-Core, 6 GB Ram, Avast Free 8.0.1489, Comodo Firewall 6.0 w/D+, MalwareBytes Pro, Super Anti-Spyware Free, SpywareBlaster, OpenDNS Premium, Web of Trust, CCleaner, Greenshot, Firefox (latest build) and, Google Chrome (latest build).
When you do something, do it with a purpose and do it on purpose.