I am thinking of upgrading to Win 7 home. I have two systems one with XP and the other Vista and because of this I am going to get the family license pack of Win 7 home upgrade. My fear is what if I need to replace a HD will I be able to install the Win 7 OS with the upgrade verison? Will I have to install the new drive load an old OS - XP or Vista- and then perform and upgrade? Any ideas? I'm sure this has been asked before, but I could not find an answer.
^ You can perform a CLEAN install using the upgrade media. You don't need an OEM version. Though if you do have a new computer, you're technically supposed to buy a full (retail or OEM) copy of Windows. However, since the OP has 3 computers already up and running with previous versions of Windows, he can purchase the upgrades and not have to worry about having to reformat. (Of course most people around here recommend a clean install anyway)