If I replace my hard drive on my laptop, how would I reinstall Windows? My laptop came pre-loaded with Windows 8.1. I then upgraded to 10. When I did a clean reinstall, I was back to Win 8.1. This did not fix my issues, hence why I want to replace the hard drive. Can I find the product key anywhere? I don't see it on any labels anywhere underneath the laptop. Also, is there anyway to get Windows 10 back without paying for it?