Finally my Windows Vista problems have ended. I was finally contacted by Microsoft and even they confirmed that my license was valid and that it should work, the only solution they gave me was to reinstall. But to reinstall without preserving my stuff, because the option of reinstall preserving my stuff was grayed out.
So I had to format my hard drive and reinstall everything, but with a little change, I installed Windows XP Professional SP2. I think I won’t install Vista again unless Microsoft completely drops Windows XP support and made changing to Vista mandatory.
Having to reinstall everything has made me lost a lot of time (BTW, why are Visual Studio 2005 service pack so slooooow installing?) but after the switch to XP it feels like I have bought a new computer or made an upgrade because everything is running a lot faster and smoother.