Help with the nasties...

I have an infection and this one seems particularly difficult to fix.

I am running an XP Pro SP3 machine with McAfee Security Center. I have followed the instructions suggested in the sticky. I have run hijack this and found several items that needed fixing, but after rescanning, the items are still showing in the scan log.

I cannot boot into safe mode.

System restore will not restore to a prior date.

I ran SAS and did a 2 hour scan and found 70 items. Said it was fixing and then needed to reboot. Upon reboot, I got a number of runtime pop-up errors, so I am unsure as to the success of the SAS scan.

I ran Combinefix and various items were found and removed and system rebooted.

Next I ran Malwarebytes anti-spyware. 2 hours later, found 20 items. removed and rebooted.

Upon reboot, McAfee went crazy saying it was catching a bunch of trojans and removing them, but in fact they are re-propigating.

Now I am also getting some Security Center fraud pop-ups.

I am really at a loss because I cannot seem to be able to fix this.

I would greatly appreciate any assistance that can be provided so that I can take the necessary next steps in order so as not to mess things up futher. Would like to avoid a reformat if possible.

Thanks in advance!

Scott