Installed vista, ran fine for a few months. Then installed some automatic windows updates one of which apparently voided the OEM license key which I bought from OCUK. I rang up microsoft and explained what had happened, they said is fine and they would give me new license key, but only if I tell them the brand of my pc. I let them know it's a self build, they say they can't help me and that I shouldn't of purchased an OEM version. Now I have to buy another copy.