Microsoft should just admit defeat and give Windows 10 keys away for free
techradar.com
techradar.com
There will be a water mark on the bottom corner of the screen, and a couple of the settings will be difficult to change, but all the upgrades work(if you want them) There is no expiration with functionality either.
I had to reinstall win7 on that system recently, and it absolutely refuses to do the online registration for it even though it's a valid (MSDN) license key. I think maybe they took the servers down or something because I get a comms error. So now after 30 days it keeps popping up a dialog box every 10 minutes saying that "I may be the victim of counterfeiting". How helpful of them.
I still don't have a solution for this so if anyone has an answer I'd be glad to hear it.
Second option is get a laptop/prebuild PC with Win7 key already burned into the bios and run your software on it.
Also known as the vast majority of users. They might manage if forced, but the vast majority of users are too scared to even try
Edit: After reading article, indeed above method is noted. Also many people will never need to enter product keys since they're embedded in their hardware by OEM's...