I installed the upgrade version before over my win xp home but, can't remember how I did it. Right now, I managed to get win 7 32 bit on booting from cd not upgrade option, but now it rejects the product key I guess because it's for upgrade only? I had the 64 bit version on before which is what I really want on there now but, I don't get the option to boot from cd so can't do it. I also made a 32 bit universal disc and a 64 bit universal from the upgrade discs so I could install just, the home premium version only or, will that not work with the upgrade version key either? I have 2 pcs when the pc crashed, I took the drive out and put it in the working pc which has the same 64 bit upgrade disk on it except, I purchased a key to upgrade it to win 7 pro to format it then, put it back in the broken pc so I could start my install. I have a retail version of xp home which I installed but, was not allowed to upgrade from that OS. I did it before but, just can't remember how I did it. All help will deeply be appreciated Thanks!