My wife and I planned to upgrade a couple of HP desktops we had. Due to a bunch of proprietary HP stuff we ended up buying new motherboards, GPUs, PSUs, and processors. We kept the old RAM sticks we had and the hard drives. With one computer we got everything installed incrementally and is working great so far. With the other computer, I put everything together at once and we had a problem booting up Windows. I ended up reinstalling Windows but now it needs to be activated. I can't find the original product key to activate Windows and I'm starting to worry I'm gonna need to buy a new Windows key. Do I have any other options here? This is getting really frustrating. To be clear, I'm looking to do this all legally, it's just really annoying that I already was using Windows and now I can't.
New parts:
MSI B550 Tomahawk Max Wifi
AMD Radeon RX 7800 XT
AMD Ryzen 7 5700X 8-Core
You've basically built a new computer; generally that means a new license. There's still a few things you could try though:
MS is generally pretty flexible regarding personal licenses and use. As long as you aren't trying to run the same license on multiple machines you should be fine. What you can't do is move the license from the OEM machine to your new custom build and expect the OEM machine to remain licensed.
This is the right answer. OEM keys are tied to the hardware so you technically need a retail key. The HP machines were almost certainly using OEM keys (chalk the first one working up to luck I suppose).
That said, by calling the licensing clearinghouse on the phone I have had them activate stuff that they probably shouldn't have so it's worth a shot. But I haven't had to call them in over 10 years so YMMV. If you call them you'll need the original OEM key from the sticker or by booting up the old PC and pulling it from WMI.
One note about pulling it from WMI: if you got a free OS upgrade (i.e. from 8 to 10) you may have been issued a new key that's different from your original OEM key. This might cause some issues when talking with the agent.
Your luck with phone activation may be different with different agents too, so it might be worth calling back a bit later if you don't succeed at first.
Ah good point. Cheers.