The OS that came with that machine dies with the motherboard. However Microsoft has never wanted to push this to a legal challenge so it's time to call Microsoft to have them fix it.
If you call in with a raving mad demanding voice you may be sent away. It's a common problem and has nothing to do with diagnostics. It's all about the well discussed areas of OEM versions of the OS that die with the motherboard. If you claim it's the replacement motherboard for this model, then it's just a matter for the call to correct and get a new key.
I recently installed a new motherboard for my desktop Presario Windows 7 64-bit. The same model motherboard that I had already.
The first few times I booted my computer there were not any problems. My drivers automatically installed and everything seemed to be as good as it was before my motherboard died.
However, after I restarted my computer the third time, I got a message on the bottom-right of my desktop screen that said I need to authenticate my version of Windows. I put in my Product Key from the side of my tower and everything was fine again. The message was cleared.
The next time I booted my computer I got the same message that I needed to put in my Product Key. I did the same steps as before and got the same Validation message. I restarted my computer to see if this would be a problem again, but my computer never booted to Windows. I was stuck on the loading Windows screen.
I did the diagnostic tests that are shown before Windows starts, but it didn't fix my problem. I am able to boot in Safe Mode though. I did a few virus and computer diagnostic scans, but nothing fixed my problem. I searched online for how to enter the Product Key and came up with a few options. There were no options to add the Product Key with the fix going through Control Panel, System, and then clicking on a button or link on the bottom of the page. There was no link nor button to click on that I saw on images online. I also tried the CDM.exe trick where I put in my Product Key, unless I did it wrong.
Does anyone have any ideas on how to fix this?