Kind of an Odd reinstall question

My friend is rebuilding a computer for some people and he ran into an issue that he hasn't seen before with the OS installation.

He then asked me about it and, to be honest, I haven't see this before either so I thought I'd ask here.

The machine came with the retail version of Windows 7 Home Premium 64bit (Upgrade) with SP1 installed on it. (have DVDs and product key and the case the OS came in, and it's definitely legal)

At some point the users bought one of those little plastic cases Microsoft sells that doesn't contain media...it contains a valid product key for Windows 7 Professional 64 bit and instructions on how to upgrade. They upgraded the computer to Windows 7 Professional 64 bit through that upgrade process.

The machine is sitting now freshly formatted with new hard drives and no OS.

Does he have to reinstall Windows 7 Home Premium 64bit (Upgrade) then re-install the upgrade? Or can he use the custom install and just load Windows 7 Professional 64 bit using the key that came with the little case containing the Windows 7 Professional key?

Just off the top of my head, it would seem to me that if he were to try reinstalling the original Windows 7 Home Premium (upgrade) it would say the product key is invalid (since it was "eaten" when the machine was upgraded to Win 7 Pro)

Anyone go through this process before and have some tips on how to handle it?

The home premium key was not "eaten" by upgrading to 7 pro. He essentially has two copies of windows now. To install 7 Pro, he will need a 7 pro disk, however. You can download the iso from windows for any version for free, you just activate afterward using your key. If possible, I would suggest this method over installing home first, then upgrading.

^ That largely depends on the version of 7 Pro purchased. If the purchased copy states "Upgrade," then he has to go Home >> Pro.

If it is simply a Windows 7 Pro x64 copy of Windows then just as ninjacore stated, you can simply install Pro and not worry about it.

If you do have upgrade media, this article should be useful for you.

http://winsupersite.com/article/windows-7/clean-install-windows-7-with-upgrade-media-128512

this is why I always tell people to steer clear of the "upgrade" media and just buy the physical disk or download one and pay for a key that way, the upgrade methods are always less than user friendly

If the price were equal, I'd steer people in the same direction, but if there are working methods to install the upgrade media "clean" and there's a significant savings, I can see benefit in going with the "upgrade" path.

Been swamped and only now got a chance the read the replies.

Thanks to all who responded. I'll send him a link to this thread so he can decide how he wants to handle the situation.

I'm just glad I bit the bullet and bought Win 7 Pro x64 so I don't have to use the work-arounds mentioned...

notarat said:

I'm just glad I bit the bullet and bought Win 7 Pro x64 so I don't have to use the work-arounds mentioned...

Click to expand...

That is assuredly the easiest option.

After Windows 7 came out I went to buy Windows 7 Ultimate. Unfortunately all they had were copies of the upgrade version. I bought it and tried it. I built the computer a few months before and did see any sense buying Vista for it. I ran the free Windows 7 beta on it until Windows 7 was available for sale. Like it recommended I erased the Windows 7 beta first. I did a clean install with the Windows 7 Ultimate Upgrade disc with no problems. The install did not even ask to very if I was eligible for the upgrade.

I have seen people talking about this ever since Windows 7 came out. Here is an article on Paul Thurrott's Supersite for Windows about it.

Clean Install Windows 7 with Upgrade Media
http://winsupersite.com/article/windows-7/clean-install-windows-7-with-upgrade-media-128512