Why am I getting this product key error?

Validation will detect and may disable or remove "activation exploits" which is software that circumvents or bypasses Microsoft product activation, validation, or licensing components. The presence of activation exploits indicates that a software or hardware vendor may have tampered with genuine Microsoft software to enable the sale of counterfeit software. Activation exploits may interfere with the normal operation of your software.

So basically, they think your laptop is running some software components which may be pirated.  You can try to validate your copy by going here.  If validation fails, you will be provided a phone number to call to help resolve the issue directly with Microsoft.