Hi shai, welcome to the forums.
1. C:\Program Files\Alwil Software\Avast4\ashQuick.exe
2. My opinion, AVG (used this pre avast), for my usage slightly less resources than AVG - Norton NAV 2004, no contest, post on these forums atest to the fact that NAV is a resource hog, bloatware and a real pig to get rid of when you try to uninstall it.
HTH David