Also, here's a few quick things to check (assuming Windows XP):
When you get the problem fixed, immediately switch to Opera or Firefox and stop using MS Internet Explorer immediately! And be careful what you download and install.
Good luck.
I got hammered in the last few days by these bastards.
It really should be illegal. Why shouldn't it be. The guys who release this stuff should be in jail for all the havoc they are causing to the US economy. And it is not a minor inconvience, they are causing major harm to normal internet users like you and me but moreso to the whole economy in general.
Anyway to the original poster, you can regain control of your system (in the long-run the virus files have to be deleted) but in the short-term, the simple fix is ...
Turn OFF in Tools, Internet Options, Advanced, Enable third party browser extensions.