If the laptop has a COA sticker, activate with the Product Key on the sticker after verifying System Files integrity as Bill2 suggests. SFC -SCANNOW Command
If you bought your laptop 6 weeks ago from a store, you have one-year tech support to help you with this.
If it has a COA sticker for your installed OS, then it should activate with the key on sticker or else you have been defrauded.
Where did you buy your laptop, and what happens when you try to activate with COA key?