Windows 10 Activation Fails with Error Code 0xC004C003

[Karamjit]

“This product key doesn't work,” the error message reads

Windows 10 was released earlier this week and millions of computers have already been upgraded to the new operating system, with Microsoft promising a very smooth experience for everyone performing this upgrade.

As it turns out, however, things are not running smoothly for everyone and plenty of users who are upgrading from Windows 7 or 8.1 and then attempting to perform a clean install are experiencing activation issues, as the process fails with error code 0xC004C003.

Posts on Microsoft's Community forums point to an error message reading the following:

“This product key doesn't work. You might need to get in touch with the store or company you brought Windows from, or you can buy a new key from Microsoft.”

How the activation process works

Microsoft simplified the activation process in Windows 10 to make it easier for users to upgrade from Windows 7 and 8.1, and you can read all details provided by the company in the box after the jump.

But in short, Windows 7 and 8.1 users who upgrade to Windows 10 are provided with a generic key for the new operating system that is then re-used when performing a clean install.

If you install Windows 10 for the first time ever (without upgrading from a previous Windows version), then you need a new key and you cannot use a Windows 7 or 8.1 product key. Right now, the only option to address this is to purchase a new key from Microsoft.

In other words, some of the users who are upgrading from Windows 7 or 8.1 are treated like new Windows 10 users, even if they already purchased a previous version of Windows.

Microsoft says that in most of the cases, this error is caused by server issues, and recommends users to reattempt activation after a few hours. Right now, however, many claim that waiting doesn't make any difference, so if there's indeed some issue, Microsoft had better come up with a workaround very soon because the number of upgraders is increasing at a really fast pace.

From

[straycat19]

Windows 10 is crap. I created cloned SSD drives of 15 machines and then put the cloned drives in the systems and verified that everything was working properly. I then tried to run the upgrade. 11 of the 15 failed. The 4 that succeeded I tried to do a clean install on and none of them would activate. All these machines had the retail version of windows 7 pro installed and it was completely updated prior to cloning the drives. The cloned drives were exactly the same drive as the original drive: Crucial M500, Samsung 830, 840, or 850 EVO or Pro, and OCZ Vertex 4. I always buy drives in pairs because originally I would mirror them so if one failed I still had a good drive but since I have several large NAS units now, only the OS is on the SSD and everything else runs from a separate HDD backed up daily on a NAS. If Microsoft thinks I am going to buy new licenses they must be high on Meth.

I will wait till Windows 2025 comes out before I attempt another upgrade, until then I will continue to run Windows 7. (Did I mention I still have two desktop systems running Windows 98 with games from 97-99 on them.)

[Kalju]

I have no succeeded in two days in a row to make a clean installation, ie, everything worked fine, but did not downloaded activation from my Microsoft account. Only yesterday succeeded without any trouble - three times, three computers.
I wipe all partition and formatted, then installed from USB (created with Windows 10 media creation tool).

[banned]

I will wait till Windows 2025 comes out before I attempt another upgrade, until then I will continue to run Windows 7.

LOL. You are way ahead of the times with Windows 7 my friend. I'm still on XP :D

Maybe I will update to 10 when I want my entire life in the cloud.