Cosmo_3 :
This PC is second hand but they guy who i bought it off built it himself so he most likely installed it onto the hard drive himself
So we have no idea....:lol:
Go through the above links and see if it is 1. Valid, and 2. can be linked to your MS account.
If that fails, you will need to purchase a new OS for your new PC.
And eitherway, you need to do a full clean install on the new system.
For future reference,
for any used PC...you need to do a full wipe and reinstall of the OS and everything else.
For your protection as well as his.