Windows Upgrade Help and more

I’m trying to upgrade my Windows 10 PC to Windows 11, which it says is compatible. The upgrade itself goes through, but afterwards I get an activation error (0xC004C003). It says Windows isn’t activated, even though my Windows 10 was fully genuine and activated. I’ve tried the activation troubleshooter, but it just says it can’t activate right now. Has anyone else hit this and found a fix?

That error usually means the activation servers are having trouble verifying your license after the upgrade. First, make sure you're connected to the internet, then open an admin Command Prompt and run "slmgr /ato" to force activation. If that doesn't work, you might need to use the Activation troubleshooter and select "I changed hardware on this device recently" to link your Microsoft account license. Give those a shot and let us know if it sticks.

Agreed. Yeah, same here. Just make sure you're signed into the Microsoft account that has your digital license linked.

+1 This happened to me. I just left the PC connected overnight and it sorted itself out by morning.

I had the same problem. Running the activation troubleshooter and selecting the "I changed hardware" option is what finally fixed it for me. Hope that helps.

Same here. Yeah, that trick works for a lot of people, but if it didn't for you, have you checked if your Microsoft account is properly linked to your digital license?

This happened to me. I had to call support and they fixed it on their end by reissuing the license.

I'm experiencing this too. Would love to know if anyone found a fix.

Yeah, You could also try using the Activation Troubleshooter again, but specifically choose the "I changed hardware on this device recently" option. Another option is to contact Microsoft support directly—they can often push a reactivation through on their end.

Following these steps fixed my issue as well.