All looks just fine.

I downloaded the newest Avast a few days ago and now every time my computer boots I get a warning about a virus being moved to the chest. It's identified as Win32:Malware-gen.

Do you still getting these warnings?
If you do, can you tell us the exact name with path of detected file?

Also, could you go here:
C:\ProgramData\AVAST Software\Avast\report

…and attach here “BehaviorShield.txt” log