A group Policy blocking avast is not normal. At all Eddy. I would suspect 0Access. That might imply an IFEO blacklist blocking Avast!.

Go Here

Download and run: OTL, Malwarebytes Anti-Malware & aswMBR

Attach the following log files in your next reply.

-OTL.txt
-Extras.txt
-aswMBR.txt
-Malwarebytes.txt

After that, I can ask a remover to come help you if any problems are present.

Edit: Can you try to re-install AVAST!?