I just purchased a new HP desktop, INtel core 2 Quad processor, 64 bit performance with 8gb of ram, 1 Terrabyte hard drive. It came with Vista home premium 64 bit edition. I had previously purchased Vista Ultimate for a laptop that no longer works. When I downloaded Vista Ultimate I put in the 32 bit instead of the 64.....I am not able to do a restore to go back to the way I purchased it. I am not very computer savvy. Can anyone please help??? Thank you. And what would be the down fall for keeping the 32 bit installed (somone had told me I wouldn't be using the full capicity of the computer) Thanks again.