Finding an .iso or other method of reinstalling windows 8/8.1

Question

I have a desktop PC I built and run windows 8.1 on. I've migrated the OS to new hard drives twice and changed the motherboard and various other hardware but in the process it has developed lots of weird, intermittent problems that are increasingly becoming a nuisance.
I would like to do clean install, just back up my music and other files to an external drive and then start over. But I cannot, for the life of me, find the original disk that it came on. The packaging for the software says "Win Pro 8 64Bit English 1pk DSP OEM DVD". I need to download an .iso or other file that I can use to reinstall windows 8 (and then upgrade to 8.1).
I found this thread: Where can I download Windows 8 legally, from Microsoft?
But when I ran the EXE and entered my product key (still have the sticker) it says "This product key cannot be used to install a retail version of windows 8"

Is there a similar solution that will work for the version of the software I have? Or is there another way to do a clean install of 8.1?

Answer 1

Microsoft has a Media Creator tool that will assist you in creating a bootable Windows setup DVD or bootable USB drive.

Clicking the Create Media button on that page should download an application, which downloads the setup files and burns them to either DVD or USB media.

I'm not sure if your OEM key will work with this method or not as I don't have an OEM key to test with.

Methods exist to change what types of key the setup program accepts, but I'm not sure what effect doing this would have on license compliance.

[EDIT}: I see you may have tried the Media Creator process before. I missed this when I initially read the question.

Microsoft also has a media replacement service that you may be able to use to obtain new media.

You might also be able to use the System Refresh feature to reinstall Windows. I'm not sure if this requires media or not as I've not used it