Windows 10: Windows 10 deactivated after mobo replace.

Windows 10 activation is on a PER COMPUTER basis. Each COMPUTER has it's unique hardware profile stored on Microsoft activation servers ONLY. Let's say you go to your friends house and he has a computer with a Windows 10 that will not activate. You log into his computer with your Microsoft account login. What happens? His Windows 10 on his computer will stay de-activated, because a Microsoft account has nothing to do with activation.

Windows 10 will activate upon one of three conditions:

1. It is an in place upgrade from a currently activated Windows 7, 8 or 8.1. Windows 10 will read the previous license information from the previous OS and use that to both activate Windows 10 and push that hardware configuration information onto Microsoft activation servers for future use.

2. A valid Windows 10 Retail, OEM or other product key is provided (not the generic key generated from an upgrade). Windows 10 will use the valid product key to both activate Windows 10 and push that hardware configuration information onto Microsoft activation servers for future use.

3. If there is no upgrade and no product key is provided (such as a clean install onto a blank hard drive), Windows 10 will calculate the unique hardware configure and look on Microsoft activation servers to see if the hardware configure was previously pushed by situation 1 or 2 above. If it finds that Windows 10 was previously activated on that unique hardware configuration, then it will activate based upon that - without any MS account ever being used to log on.

4. If it doesn't find that unique hardware configuration then it will not activate, no matter how many users log onto it with the Microsoft accounts until a product key is provided to create situation 2 above.

Even though two computers may have the exact same hardware (make and model) there will be several serial numbers for the motherboard, CPU, and LAN MAC addresses that will be unique. Those are a large part of what generates the unique hardware ID used for activation.

 

This isn't complicated. All oem versions of MS OS is good for the life of the computer. That is defined as the life of the MB. Change the MB and an oem version will no longer activate. You can debate how MS knows all you want, doesn't change this fact. The retail version works differently. If you have a retail version of a qualifying OS, load it and then update to Win 10. If not you'll have to revert back to your old MB or buy a new Win10. Some people have been able to get a MS customer support person to feel sorry for them and give them an activation key, but I wouldn't count on it.