XP(Pirated) upgrade to Vista(not pirated)

Hi, I was wondering if you can upgrade from a pirated XP to a Vista. I would tell you the whole back story to why i have a Pirated Xp but i would rather not since it waste time.
                                                                                                                                       Thanks, Rob

Yes. But you have to back up everything on something, then install vista. you cant "upgrade" as far as I know. You have to clean install.
Yes. Yes it works

so i dont have to buy the full version right? i could just buy the upgrade version?

oh btw if i buy a OEM operating system and i change some parts in the pc what will happen?

Hmmm... im not sure.. anyways, id go full version anyday.. and a clean start.

if you change a certain amount of parts, your oem wont work...

If you get the full version can you uninstall then reinstall on another hard drive or something?

Just get a removable harddrive and put all your shit on it. Then format the computer's harddrive and install vista. move everything back.

risky