Windows 10 Pro will not activate

Hi everyone!

I'm in a bit of trouble, my Windows 10 will not activate.


Before Win 10 my laptop was running Windows 7 Professional, (legal license offcourse), when Windows 10 was released i performed the upgrade through Windows Update. The installation went smoothly and Windows 10 installed and activated like it should.

After this i wanted to perform a clean install, so i removed all partitions and completely reïnstalled Windows 10 using the media creation tool. Once again Windows activated like it was supposed to.

Recently i have to sometimes work in Linux for school, so i decided to set up a dual boot system. I messed up my first attempt, so i decided to start from scratch and successfully set-up Windows 10 and Linux Mint alongside eachother.

For some reason Windows 10 Pro will not activate and it gives me the well known Errorcode: 0xC004C003

I no longer have the Windows 7 Pro key, the sticker on the bottom of my laptop came off and i thought i had kept it in a safe place but i can't find it anymore.

So i went to microsoft.com and chatted with a nice support tech, explained my situation like i've done so in this post, and he tells me he needs a Windows 7 license key..

I was under the impression that once you've performed a successfull upgrade to Windows 10 (with a successfull activation), a unique code is generated based on the hardware in your system so in the future no codes are required to activate Windows?

Now this tech guy says without a Windows 7 key he can't help me, while i have already performed 2 Windows 10 installs that both activated :S This is so confusing and contradicting to me. Has anyone experienced similar problems?
What am i supposed to do now? Go out and purchase a license key to activate my OS, which previously activated without a problem?

Did you make any backups of your computer when running Windows 7?

NavyLCDR said:

Did you make any backups of your computer when running Windows 7?

No i didn't, from now on i'll take making back-ups more seriously :)

I just spent over an hour chatting with a Microsoft Support Agent, unlike his co-worker who i mentioned talking to earlier, really went the extra mile for me.

I explained to him i had lost my Windows 7 Pro license key that came with my laptop, and he asked me if i had an invoice for my laptop and if so to open it up on my desktop, he then took over my laptop remotely, viewed the invoice and executed some commands in a DOS prompt, and uploaded what i could glimpse a system profile to a MS server.

Then he said he showed the invoice to his superior, and if it was alright with me to wait 5 to 10 minute while he would talk to his superior. When he was done talking to his boss he said MS would give me a Win 10 Pro product key. With the remote control still running he activated my OS and gave me the new product key.

While i'm not a huge fan of MS, i certainly didn't expect this!