Well i have an upgrade disc from campus for windows 7 ultimate. I have my parts ordered for a new PC build and they will be here in a few days. I was originally gonna use my old vista oem disc for this new build and upgrade it to windows 7 with the disc i got from school, but found out that u can only use oem discs once
.. So, im going to have to purchase windows 7. My question is, i will purchase windows 7 home premium oem, can i use my upgrade disc i got from school to upgrade it to windows 7 ultimate? or do i have to buy the retail version for the upgrade to work?