Reinstall windows 8 upgrade with a windows 8 oem disk?

I have a windows 7 PC that I upgraded to windows 8 pro awhile back. This PC has been having some issues so I wanted to do a clean install, but I didn't make an ISO image of the windows 8 upgrade when I downloaded it. I do have a windows 8 system builder disk though from a different PC I built. Is it possible to do a clean install of my upgrade using the "system builder" disk and my upgrade key? I read some posts from a year ago saying you can do a clean install using the upgrade CD but didn't know if the system builder could be used instead to accomplish the same thing?
Thanks

Answer

I just did a clean install of Windows 8.1 Pro on my machine using a previously purchased Windows 8 upgrade key.

First, I downloaded the full 8.1 ISO using this procedure. I used my own upgrade key to initiate the download.

Then I installed 8.1 Pro using a generic "trial" key for Pro version

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This installs a non-activated trial version of Windows 8.1 Pro.

And then I activated that freshly installed version using my upgrade key. It all worked without any problems.

So, my suggestion would be to forget about any disks you might have. Download the full ISO from Microsoft, install it and then activate it with your key.

But if you insist on using your system builder disks specifically, you might find yourself in a situation when system builder disk refuses to accept an upgrade key. In that case you might try using the "trial" key for installation and then using your upgrade key for activation.