Windows XP or Vista

Your question should be Vista or Windows 7. Do you have XP apps (not games) that you need to be able to use? If so, windows 7 has virtual XP mode built in where Vista doesnt.

Forget XP. No support for XP in the near future and going Windows 7 will pave the way for direct x 11 capabilites for your gaming needs in the future provide you get a direct x 11 video card as well.

if ur asking the question, then ud better be safe and go with xp, win 7 is comming out soon and ull be alot more comfortable with that than vista

I have already found that some shops are selling Windows 7 with Crack. What about those W 7? Did not it come out very early !

dont buy cracked windows
wait for msoft to release it, or wait for a retail or oem crack

Stick with your current OS, if not go with Vista SP1 x64, then decide to switch to Windows 7 x64.
I'm sure you don't want to be waiting around for the next 3 to 4 months for an OS to be released.

Dat's what I say.

^ SP2 is out so it might be better if he sticks with vista64 SP2.

and then wait for all the kinks to be taken out of win7 x64 and get that.