It sounds more like you've been infected with a trojan such as Zlob, which turns off System Restore and often removes icons from your Start Menu. It will also disable 'regedit', reporting that the System Administrator has denied you access, or words to that effect.

Another sign is VIRUS ALERT! appearing in the clock, though this doesn't always happen.

It's fairly easy to remove these things if you have the experience to do it, but starting your PC in Safe Mode and running anti-virus and anti-spyware from there can be a good start.

You'll also need scripts to correct the registry entries that Zlob has either added, removed or modified...

I can help you with this, but later this evening... around 10.00 GMT after I get back from the radio station and and at my home computer.

Alternatively, do web searches - though be careful, because some sites require registration and then tell you nothing. Others merely point you to some software download that won't work unless you pay.

Sorry this is a bit garbled, but I'm supposed to be... erm... working!