I'm getting error code 0xC004C003 when I start up my homebuilt PC. I've looked through various forums and tried reaching out to Microsoft Support, but nothing has worked. I've tried the activation troubleshooting, and running it as an administrator didn't help either.
I've had this PC for over a year without any significant changes or clean installs, and I've kept my system up to date with all updates. Unfortunately, I no longer have the product key from when I activated it the first time.
Has anyone else run into this issue? Any advice on how to fix it would be really appreciated!
5 Answers
What version of Windows are you using? Where did you acquire your activation key from? That info could help narrow down the problem.
If your key wasn't purchased from an official Microsoft source, it might be illegitimate or a volume license that got flagged. Just something to consider.
Are you the original buyer of the Windows OS? Just checking because that can make a difference.
I'm on Windows 11 Pro, and I got my key directly from Microsoft. Have you tried getting in touch with their support team?
It sounds like your key is blocked, according to the error code you mentioned. You might need to dig into your Microsoft account to pull a new license, or you'll have to get a new key from a verified source.

Yeah, I did reach out to them, but no luck so far.