How do I perform a Clean Install of Windows 7

As you've discovered, the "official" Microsoft Windows 7 Software Download page does not work for OEM product keys.  That's because under the terms of the license granted to your computer's manufacturer (your OEM), it is the manufacturer, not Microsoft, that is responsible for supporting your installation.

Still, it's an uncharitable position for Microsoft to take, considering that all you're looking for is an ISO file and not "support."

Microsoft has made it difficult to obtain legitimate copies of ISO files for Windows 7 for owners of non-retail Windows 7 product keys.

As far as I know, at the present time there are two websites from which you can download an ISO file from which you can make an installation DVD or USB flash drive for Windows 7.  Each of the websites has an issue.

http://windowsiso.net/ has ISO files for all editions of Windows 7 ... but these are provided as torrents.  Torrents have a somewhat dubious reputation -- because they often are associated with malware and stolen or counterfeit software -- but as far as I know, this site has legitimate files.  You will need to install a torrent client to download these files.

https://tb.rg-adguard.net/public.php has English-language ISO files for Windows 7 Ultimate.  If your product key is for a different edition of Windows 7, you will have to edit the ISO file to enable installation of the edition for which your product key is valid.  There are several websites with instructions on how to do this.  See, e.g., https://www.pcworld.com/article/2044281/install-any-version-of-windows-using-any-windows-disc-you-can-find.html

Once you have the ISO file corresponding to your product key, see the following for directions on doing a clean installation of Windows 7: 

https://answers.microsoft.com/en-us/windows/forum/windows_7-windows_install-wininstalls/clean-reinstall-windows-7/0ae269fd-167e-423b-94ef-26133f89e10c

Hi,

Well if its just the disk which is an Issue for you. You can download the ISO Image from the link that i am sharing with you.

https://www.microsoft.com/en-in/software-download/windows7

Go on the link Type Your 25 Characters Product Key click on Verify and you can download the ISO Image of the Windows 7. Later you can burn it into a DVD and perform the Clean Installation.

Please let us know it that was helpful.

Sounds good. Thank you. How can you help me?

Thanks Piyush. I had already found that link, and I was informed by Microsoft support that my product key does not work there because it was used by the manufacturer.