Hello,
A retail product key can only be used on one machine.
If the old server fails to open. Unfortunately, you'll need to purchase a new product key to activate the new system.
If the old server can still be opened, you'll need to uninstall the product key on the old server to use it on the new server. The steps are as follows:
Open Command Prompt as Administrator.
Type the following command and press Enter: ****
slmgr.vbs /upk (This command uninstalls the product key from the server)
slmgr.vbs /dli (This command displays the current license information, if the key has been removed, it should show that no product key is installed.)
Best Regards,
Hania