Windows 8 pro licence transfer

I transferred the hard drive from my dead laptop to another laptop.
Now the windows needs to be re-activate again.

But I am getting the message 'The windows key is being used on another PC. Please try a different key'.

What to do ?

Its retail windows 8 pro licence not oem

try contacting Microsoft helpline. If you can emulate mac id/ physical address of lan/wifi of dead laptop. then no problem with activation. Otherwise use KMS activation tool

Activated by calling Microsft