Also, we have two other computers running Vista 64 bit and Windows 7, both of which have had Avast removed. After Avast's upgrade (free version), Skype looked like it was running, but when my husband and his friend called each other there was no sound, and then they discovered that there was NO sound at all for the games or programs on either computer. They uninstalled Avast and installed a Microsoft product, and the problems stopped.
I am not eager to get rid of Avast because it has served me well. But, it seems like Avast may be over-producing its product like Symantec did not too long ago. Too many extraneous fancy features, not enough control to turn them off. Its foot print on the CPU was gargantuan. I hope this will not be the case with Alwil.