Thanks for reply,
i tried to run it from avast folder it is working from there, but let me add it to something that this problem is not of permanent in nature.
At this moment i tried it from avast folder it worked fine similarly i was able to start it from notification area.
Computer was recently formatted and Avast is the Only protection on it , i even didn't installed the windows defender thinking that both perform the same job one will scan the activities of others and vice versa.
Thanks