Windows 10 not working

[nightlovin]

I recently built a new PC and downloaded Windows 10 onto my SSD from an USB and everything worked just fine for a couple days. I then decided to do some cable management within the case, unplugging some cable and rerouting everything to make it looked better. When I went to start my system back up it wouldn't boot at all even though everything was plugged in correctly and nothing really changed in the system besides some cables were routed differently. After awhile and some random settings getting changed I was finally able to get it to boot with the little watermark in the bottom right hand corner saying activate windows. Now I get the notification that my product key is already being used and I have no way of activating my key even though it is being used my the exact same system. Does anyone have any idea how I could fix this because I am lost on what I could do to fix this? And the key is an OEM key  

 

Thank you to anyone that might have any suggestions to how to fix this.

[Thx And Bye]

Either try to activate via telephone or contact the Microsoft support directly.