Were are you getting the money to buy these OS's?
Pardon my ignorance, but did you buy your copy of Windows 7?
If not, I have a registration key you could have, though I'm not sure on the legality of that.
"All these oses"
I'm using all the operating systems my family has used thoughout the last decade and a half.
I was just able to put my hands on a copy of XP and Vista we had lying around that came with other computers we bought a while ago.
As for another copy of windows 7, I may have to download that. (my origional copy came with the computer I'm using now)
I've already bought it, so I wouldn't think it's piracy, but if it is I hope (as far as posting this topic here goes) Badspot understands.