Windows Vista problems.

[vaio-fx]

I have vista for about 8 or so months now and I can't stand using it anymore. It has been slow and doesn't support a lot of my old games and software. The final most annoying problem was yesterday when it accused me of having a pirated copy and locked me out of windows - Pirated?? - I spent £200 on it! I managed to reactivate it but it is has made my wallpaper plain black and has stuck this annoying phrase in the bottom right hand corner of the desktop: "This copy of windows is not genuine, you may be a victim of software piracy". It has blocked me from using windows update too. It runs slowly on my PC too which is annoying if you look at the spec in my signature. So my question is, is there anything I can do to get rid of this horrible OS - and still get some money back? Is there a way of refunding or anything? I have tried to get used to this OS but its just got too annoying. Any help will be greatly appreciated. Thanks.

By the way sorry about it being so long.