AntiVirus 2012 repeatedly finding Trojan.Zeroaccess and Trojan.Gen.2

I'm having this exact same issue. Norton AntiVirus 2012 continues to find:

 

- Trojan.Zeroaccess

- Trojan.Gen.2

 

and, often, I get notifed that Norton is blocking a Hacktool.Rootkit. After several days of running scans and fixes (including power tool), I still have the problem. I have a:

 

- Hewlett Packard m9180f

- Windows Vista Home Premium (system pack 2)

- 64-bit operating system

 

I found this thread that has the same issues but didn't take any of the steps listed as the Norton responder directed other readers not to do so. Are there any suggestions you have I could take to fix this issue?

 

Thank you,

Stan