I've owned an Asus G56JK laptop for about 8 months now and haven't touched the windows product key from what it shipped with, but today on turning the laptop on I got a message to activate windows, saying the product key is already in use. Nothing hardware-related has changed in months, the only change being the addition of a solid state drive 6 months ago, and the product key shouldn't be in use (legally) on another machine anyway, but the message does not go away. How can I fix this or at least verify if it's a legitimate issue of product key theft or just some registry problem?