Trojan.Zeroaccess.B

I am running Norton Internet Security 2012.  A full system scan detected a threat named Trojan.Zeroaccess.B located in c:\windows\system32\consrv.dll and indicated that manual removal was required.  I first rebooted in safe mode and ran the scan again with the same results.  I have run the Norton Power Eraser (both regular and beta versions) and the Norton Bootable Recovery Tool but the problem remains.  I have noted that Norton also lists a Trojan.Zeroaccess Removal Tool but this only runs in a 32 bit environment.  I am running Windows 7 Professional 64 bit.  Any suggestions?