erm idiot you missed a vital part out of that guide.
All who do this, you MUST disable all windows updates and I mean all, I have Windows 7 Ultimate 64 bit and i didn't pay shit for it but if you don't disable your updates Microsoft will know and will come down on you like a sack of shit, the keys have all been used on other peoples computers who actually bought Windows 7, they have a legal right to Windows 7.
In short: disable all of your updates or Microsoft will hit you hard.