Microsoft Office 2010 on Windows 10

Certainly not a silly question.  Microsoft Office 2010 has been verified to run fine on Windows 10.

Also your license will still be valid so you don't need to buy Office again.

First try: Right click on Start button -> Program and Features -> select the entry for Microsoft Office -> Change -> Repair

If repair doesn't fix the problems uninstall and reinstall Microsoft Office.

Well I have never heard of an Office 2010 license that is really tied to how many times you activate it.  Yes there is a counter to try to prevent pirating, but the actual licensing is about how many machines you are using it on.  For instance my license is for 3 machines.  I have rebuilt and replaced many machines over the years.  If Office 2010 doesn't activate automatically, a call to Microsoft fixes it by telling them the old machine is dead (or I replaced the motherboard, ...) and they activate it for me.

Now I have heard of and OEM copy, which is one that the manufacture puts on your machine.  That might be tied to only that device.  And in this case I wouldn't know if changing the operating system is considered changing the device.  But again if that is true it isn't based on how many times you activate, but on if the license it tied to a certain device/operating system.

I had forgot about the volume license, but in fact it proves my point.  It isn't the number installs they are blocking, it is the number of "machines/devices".

On the same "machine/device" they would let you reinstall all you want.  But they consider it a different machine/device when you updated to Windows 10.

That appears to be true from the Microsoft perspective. I still have the same machine, serial number, processor etc. Every other piece of software works fine with the change.  Only Microsoft is treats this as a new install and only Microsoft is pushing me to pursue my options like "Open Office" or "Libre Office" as I am not prepared to upgrade to win 10 and purchase a new office.