I had a problem when paying with Bitcoin, the purchase was not made and I was not refunded, but when buying by paypal everything was fine, the activation was successful.

De maravilla, se activó inmediatamente y sin ningún problema, todo rápido y correcto.

Qué buena decisión el comprarla aquí, mucho más barato que en otras tiendas y súper bien.

seems a bit sketchy. havent brought it yet

I was questioning whether to purchase a Windows Key from a 3rd party at such an inexpensive price but...

I emailed Gamer's Outlet about the process for using the "Windows 10 Professional Retail Cd Key Microsoft Global" to upgrade from a Windows 10 Home edition to the Pro edition and they sent me back the instructions for a 2-step process with an intermediate Version Upgrade Key which would need to be installed before the Pro Key could be used to activate.

After installing the Version Upgrade Key and a reboot, the Laptop showed Windows 10 Pro was the current edition but needed to be activated. I purchased the above Retail CD Key and and to my surprise as soon as the Retail Key was installed it showed a fully activated Windows 10 Pro edition. Even though it wasn't necessary I rebooted to make sure the activation stuck and it came back up with Windows 10 Pro fully activated with no windows error messages.

This site is now bookmarked for any future needs.

Sketchy as hell but worked for me I guess, will make an update in case further issues. Nothing to say bad right now so i put 5 stars