hey and welcome to the forum.

first please follw this guide and attach your log.

http://forum.avast.com/index.php?topic=53253.0 (we need the logs from malwarebytes otl and aswmbr.)

a malware expert will help you from here.

about avast free you have to registry for it once a year so it will still be active.

this can be done throw the program interface or throw the avast.com

have you tried the uninstall tool for avast in safe mode? if not try that but after the malware expert have given a green light on your computer

good luck