Hello. I was recently given a Dell Optiplex 755 Mini Tower with no hard drive in it, The sticker on the bottom of the machine says it was running Windows Vista Business. I plan to put a new hard drive in it and re-install Windows Vista Business. I am trying to figure out if I need to get the 32 bit version or the 64 bit version. I have done a bit of research and from what I understand I could install the 32 bit version of vista on either the 32 or the 64 bit processor, correct? But I have also read that the product key on the Vista sticker will be specifically for either the 32 bit version or the 64 bit version. I would like to make sure that I install the correct version of Vista Business so that I am able to use the product key from my sticker. Any info would be greatly appreciated. Thanks.