Can't connect to the sync service

Dear Friends

As per the thread title

Background: I made a minor change in BIOS, to add an asset tag. All good. Upon reboot, Windows thinks I've had a hardware change! I have been through the activation troubleshooter, to no avail. 0xC004C003

I have a valid digital licence, linked to my Microsoft account, as I upgraded from Windows 7 Ultimate x64.

I've tracked the issue down to the sync service: it looks to me like Windows can't "talk" to my Microsoft account to see the digital licence.

The microsoftaccounts.diagcab troubleshooter identifies the issue, but can't fix it.

If anyone knows what to do, I'd be very grateful!

Thanks.

 

Thanks coleoptere, been through all that already, to no avail, sadly.

 

I just used KMS_VL_ALL in the end, I don't have time for this nonsense.

I was on with three different Microsoft Support Agents. Useless. None would address the actual issue, one idiot told me that the slmgr /rearm command would permanently activate my machine!

Another gave me a generic product key, and the third just wished me a Happy New Year.

Cheers all. And as Microsoft Support might say, Happy New Year!