It sure sounds like the virus/trojan we got. It's taken the admin rights. As I said, the only way we figured out how to kill it for good was a complete reformat. It's a genius piece of writing...even if it's evil, in that the code is code, inside of code, inside of code. It at first merely redirects, but when one starts to fight that, it has a trigger which causes another attack, which also has a trigger which eventually hacks the admin accessibility...and then, depending on what you try...can lock you out further.
Genius little code...very malicious, very evil. if you DO find a workaround, be sure to tell us.
Finally, this is a KNOWN trojan...and there should be a great deal of info on how to deal with it at Symantec and McAfee, they may also have a call in and support line to talk you through some of it as well.