Desktop lockout...

Hello,


<config>Windows Vista

I seem to have a fairly major problem with my PC. A few days ago I was watching a TV show online, when internet explorer opened up (I'm exclusively a firefox user), and had this page on it saying that London and Strathclyde police had found me looking up illlegal stuff (not true) and I had to pay £100 to get my computer unlocked. I quickly shut down my computer, and found out that this was a virus. I ran a scan, and a few items were cleaned up, but my PC was fine, except that things wouldn't minimise properly. I did a system restore, and then the real problem kicked in.

NOW, when I turn on my PC, the internet explorer window pops up and takes up the entire screen. I cound I could close that by pressing Alt+F4, but then all I get is my desktop background and nothing else! I can do the Ctrl+Alt+Del thing to get it to say start task manager, but then I can't actually start it!
Earlier I managed to get what looked like my whole desktop up, but found I couldn't start anything properly.
When I press the shutdown button, for a second my REAL desktop comes up, and I can see all the windows I've tried to open. But of course, it's too late, as the shutdown is happnening, and I can't work anything!

Please help!