Trojan.Gen.2 and Trojan. Zeroaccess (possibly Hacktool.Rootkit) - definitely not fully resolved

My very first post on anything but facebook.  My knowledge of computers is pathetic but I am too poor to hire someone to clean these horrible viruses from my computer.

 

I have Norton Constant Guard through my internet provider.  I had warnings about Hacktool.Rootkit and I thought I had cleaned it up but I may have just chased it into hiding.  Trojan.Gen.2 and Trojan.Zeroaccess show up every time I restart my computer or if it sits idle for very long.  Norton sends me reassurance that the problems are "fully resolved" - but after floundering around for a few days I am desperate.  

 

I am using Vista Home Premium Service pack 2 - 64 bit.

 

Any help would be greatly appreciated.