Lost 1 activation after reinstall the corrupted window.

 
Last night, due to unknown reason my window corrupted and i can not boot my PC.
I reinstall window and reinstall everything including MT4 and EA i purchased on the same PC.
I lost 1 activation after that. Is it possible to regain my lost activation?
The EA i purchased cost a couple thousand dollar. it would be a huge cost if i lost that 1 activation.
 

The reinstallation of Windows makes it look like you installed on another machine, thus the activation.

Only the Service Desk can possibly help you.