Windows 10: Reactivate my Windows 10 pro

I am trying to re activate my Windows and I keep getting error: contact my organization's support person. I don't know how?

:)

 

Reactivation Windows 10 Pro issue

I have changed my hardware recently and found that I can't reactivate Windows 10 Pro. In Reactivate Windows section, I can't find my current device in the list, only my old motherboards appeared ( MSI and Gigabyte ). My old hardware are I7-4790 + MSI H81M
Mobo + 8GB DDR3 Ram and I upgraded to I5-9400F + My new Asrock MOBO B350 or 450 something (Can't remember) + 16 GB DDR4 Ram. There is no my current MOBO in the reactivate section, only the old one appeared (MSI H81M Mobo). Pls someone help me.

Also note that I have signed in with my microsoft account that links with Windows 10 pro licence but it only shows the old mobo in the reactivate list.

 

Motherboard change unable to reactivate Windows 10 Pro -

I have searched this topic and everything seems to be almost a year old. This is a homebuilt machine circa 2015. It started with an ASUS FM2+ motherboard with an AMD A5600K processor. It was Windows 7 Pro, upgraded to Windows 8.1 Pro then to Windows 10 Pro.
Saturday the motherboard died. An exact replacement could not be located so a Gigabyte card was installed. No changes to the hard drives. Booted the machine and Windows automatically started and then did a "revert" then installed the latest updates. C Drive was in the red so I deleted all of the old install files using Windows Clean-up. Went to reactivate, checked the significant hardware change and entered my MS account information - The computer (none of my computers) were listed and now it is telling me that I have to spend $200 to buy a copy of Windows 10 Pro.
Have not yet called Customer Support as the computer is at home and I work during the day -
I do have a disk image or two that may be a year old -

Suggestions - should I just shell out the $200 and move on

TIA

 

Motherboard change unable to reactivate Windows 10 Pro -

Activate using windows 7 pro key.