Windows 81 Patched [work]: Getmyos

: If you are currently on Windows 8, you can find the Windows 8.1 upgrade patch for free through official Microsoft channels.

Projects like (found on MDL forums) provide batch scripts that integrate updates into your own legitimate ISO. You download the official ISO from Microsoft, run the script, and create a patched ISO yourself. This is infinitely safer than downloading a pre-built "GetMyOS" version. getmyos windows 81 patched