Avast wont open

ok so Im trying to fix my mother in laws laptop. I think it has a virus on it. I have downloaded Avast and Malwarebytes and installed them both. Nether one of them will open up though. Not in regular or safe mode. Windows 7 is OS.

Thanks for any help!!

Hi what error do you get when you try to run them ?

Please follow the steps in this thread http://forum.avast.com/index.php?topic=53253.0 and attach the logs here

I dont get anything. It does nothing. no matter what i try.

Hi what are the exact problems that you are experiencing ?

Can you download and run any programmes in that thread

Is this a 32 or 64bit system and do you have a USB handy