systemerrorfixer is an evil, tenacious monster. Please help!

ok, I know that several people have had problems with this program, and I've been searching forums and following step by steps for the last three days trying to wipe out the little monstrosity, all to no avail.
I tried installing and running SuperAntiSpyware 4.0, Counterspy, Malwarebytes Anti-Malware, and have also run my resident Norton Anti Virus.
None of it has helped.
I went through my add and remove programs list looking for specific programs, searched my C drive for suspicious files, have gone through my system processes manually, and I STILL can't find and rip out the nasty little sucker.
It's overtaking my screen with phoney Windows security center warnings, shuts down my computer at random ( especially durring scans or trying to dig it out of it's hideing place ) and I think it is starting to mess with my computer's log in process now too. When I restart my computer it prompts me to run an anti-spyware search before it boots up Windows, but as it doesn't seem to actually help anything and just delays windows for an hour before letting it open I am pretty sure it is just a piece of the malware.
Can someone help me do battle with this beast and get rid of it once and for all? Without tossing my PC out the window?
Thanks!