win32:sirefef-zt [Trj] virus help?

I ran Avast today and it found the virus:
c:\windows\system32\services.exe Threat: Win32:Sirefef-ZT [Trj]

I have been online and tried a few things to kick the virus, but it is still on my computer. Here is what I have done so far: ran a Malwarebytes full scan in safe mode and found what looked to be the virus. I deleted it. Then I ran FixZeroAccess and it didn’t find anything to report. Next I ran aswMBR and it found 3 infections: c:\windows\system32\services.exe INFECTED Win32.seirefefr-zt [Trj] ; windows\assembly\GAC_32Desktop.ini INFECTED Win32:sirefef-PL [Rtk] ; windows\assembly\GAC_64Desktop.ini INFECTED Win32:sirefef-PL.

Avast also keeps popping up saying it is blocking threats on my computer. The most recent was win32:zacess-[trj]. I am not sure if that is another virus or just part of the first virus. I’m at a loss for how to remove this virus at this point. Can anyone help? Many thanks.

PS. I accidentally posted this to the wrong forum. I meant to do the virus and works. Can a mod move it to that thread for me? Thanks.

Follow the steps in this thread please http://forum.avast.com/index.php?topic=53253.0 and attach the logs here