Sorry to be a noob and what have you for signing up. - but I can't get rid of this great virus/spyware that someone managed to put on my computer.

My computer was recently infiltrated somehow - and what happened was, the guy that was doing it did his work, then automatically shut me down. When I came back up i had all these fake security alerts and what have you - that was fine - but the problem was - my Norton Antivirus no longer would open and I could not reinstall it. My Spybot Search and Destroy will not connect to their servers, same with my Ad-aware. This is the main problem I am having - it won't let me visit anti-spyware/virus servers - it just comes up saying that it is "unable to connect, even though it appears there is nothing wrong with the web site" - obviously the guy who got me knows his stuff.

I finally managed to download a trial version of Nod32 - it cleaned up most of the viruses and what have you (i.e. those fake secuirty centre alerts and other programs that would install itself in background). What still has not been fixed is this strange server thing - where it will not let me visit any of these sites - or download from Spybot so that could clean it for me!

Would I have to format my computer? Although, I would prefer this to be the last resort. Any help would be much appreciated, I'm at a loss.
Cheers.