http://windows.microsoft.com/en-us/windows/preview-iso
https://insider.windows.com/

If you need a fresh system would suggest joining the insider program and putting the ISO on a USB or CD/DVD! can keep old files if do the upgrade and it's free ^_^ / we can all talk to windows about better flash integration for the games in browsers+windows processing in general /windows functionality in general etc

can let everyone know that R2 games program clients and flash works in each of the browsers once installed to access the games