If you are using Windows 7 or 8.1 you are able to upgrade to Windows 10 starting today. Make sure to download the AMD Catalyst 15.7 Driver with Windows 10 support.
For more information check out this Microsoft blog: http://blogs.windows.com/bloggingwindows/2015/07/28/windows-10-free-upgrade-available-in-190-countries-today/ 
