Nasty Rootkit

I seem to have picked up a particularly nasty rootkit. I hope someone can help because I have been scouring the web for two full days now and I have not turned up anything that works. It will not let me do much as far as running AV programs. It will Not let me run Malewarebytes nor Hijack this. It will not let me run Avast nor Nod AV programs. It will not let me run Regcure nor Registrybooster I was able to run Spybot and it picked up something called "UACd.sys" which I found out from a web search is a virus. It was located here: HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\UACd.sys (and in several more ControlSets) With this key: \systemroot\system32\drivers\UACssibivkdiv.sys I took a chance and deleted all references to this in my registry and after a reboot things seemed to work again. However, later (after a second reboot) the problem seemed to return and I am no longer able to run these programs once again. I searched the registry once again for traces of UACd.sys but did Not get any hits this time. I am beginning to suspect it is a mutating rootkit. Any ideas as to how I can find out what I got and how to get rid of it? I would GREATLY appreciate any assistance anyone might be able to provide. Thanks, BigIron2