I purchased a copy of Vista Ultimate OEM 32-bit from newegg a while back - have only used it on my one PC. I am currently in the processes of upgrading my PC with all new components and want to make the jump to 64-bit to take advantage of more ram. My friend will let me borrow his copy of 64-bit Home Premium OEM also purchased from newegg - will my key for 32-bit Ultimate work with his 64-bit Home Premium OEM disc - if so, will I be able to install Ultimate 64-bit from his disc or is it only limited to Home Premium? I'd prefer not to have to purchase another OEM disc for 64-bit since I've already legally purchased the 32-bit version. Thanks!