As I said I'm not sure I got infected from here - there's a LOT of malware making the rounds these days and the folks that invent it are getting VERY smart
One in particular loads a fake Anti-Virus system - and usually disables existing software like Norton, McAfee, AVG - and also turns off your system restore and won't let you enter safe mode.
They want you to "buy" their software which probably does fix the problem seeing as they invented it - but of course you shouldn't do so.
This article gives some background but I don't endorse their "fix" - having not tried it. It does detail how the computer browsers are hijacked, downloads - especially of anti-malware programs - are prevented etc...
How To Uninstall/Remove Antivirus Live Virus Removal Guide – SoftSailor
In the end if SuperAnti-Spyware doesn't at least give you enough of a temporary respite to get McAfee, or other programs running again you'll be needing to have your hard drive removed and "cleaned" as the malware is in the registry and can't be cleaned when the operating system is running. That's not a technically demanding issue for most computer shops - just a pain in the ass.
With so much other junk on my comptuer bogging it down I actually went the extra step of backing up all files and programs, reinstalling my OS and starting fresh.
That actually was a pretty smart thing to do as I think I'll get more life out of this computer as it is. But thanks again for Ian for addressing this. I have a feeling his is not the only site that's spreading the infection by far
Sounds like a lot of people I know I have picked this up via Facebook too... again, no one doing anything or downloading anything or running an exe program - just a Trojan that takes over a computer and wreaks havoc.