You're welcome! You've pretty much got it right. I would clarify a couple of things. 1) I'm not sure you can upgrade directly from Win7 Enterprise trial to the final. It's activated alright, but it might not count as a previous version of Windows. So if you went that route you could end up installing XP or Vista anyway before going to Win7 final. I only mentioned it in case you wanted to try out Win7; but If you'll take my word, it's great! About not installing it on a primary computer, I would not hesitate to do so. Enterprise is targeted for business users, and MS doesn't want the blame if specialized business apps don't work on Win7. Hence the warning. Win7 Enterprise trial is the final version of Win7; for the home user, it is fine to use on a main computer. 2) You don't have to format and clean install going from Vista to Win7. That route (supposing you still go for 64-bit) can truly perform an upgrade: transferring files, settings, and programs. Of course you can still do a clean install. I really can't recommend for someone else, but here's what I would do personally: start with Vista. I'd want to take full advantage of my new hardware with 64-bit; that rules out XP. I'd also want to make sure I was able to decide between a true upgrade or a clean install when it came time to go to Win7 final; that rules out the Enterprise trial. All that's left is Vista, and with SP2, it's not half so bad as many people make it out to be. Now I know you will have a new hard drive, but if you really want to upgrade, it would not be difficult to image from the old drive onto the new one.