OK, I'm a bit further on, but not out of the woods yet....
I can't get anything to run in my own profile, because all menu options that allow programmes to run have been deleted by the virus. Also, I can't run as Admiministrator because Task manager and "Change user" are also missing...
I can run as Administrator in Safe mode, but as wery little is running in the background in Safe mode, I figured a Hijackthis scan wouldn't reveal much about my infection.
So.....I tried running SDFix in safe mode and it actually ran! This was the first "Anti-virus-type" programme that has managed to run for nearly a week now, so I was really pleased that I had some progress of a sort..
SDFix identified several Trojans and then re-booted in normal mode into my profile. The PC's behaviour is now far more usable, with only the occasional popup asking me to update Antivirus2008, which I can just cancel. This is a LOT better than before, when popups happened evert few seconds, and my broadband was almost unusable.
My main worry is that I still haven't got most of my startup menu items, such as "Run" and "My computer" (and orthers). Would it be easier to delete my profile and create another one? Presumably the new profile would have all the missing menu items on it?
Anyway, I have run a Hijackthis scan in my present situation and will try posting it to
http://www.2-spyware.com/forum/forum8 .......
Thanks for all the help.....I'm sure I am a lot nearer a fix now.