DOWNLOADING WINDOWS 8.1

 I CANNOT DOWNLOAD WINDOWS 8.1 ON MYCOMPUTER(WHICH CURRENTLY HAS WINDOWS 8 NON OFFICIAL VERSION). I HAVE TRIED EVERYTHING BUT IT IS OF NO USE. I HAVE TRIED...

1. DOWNLOADING ALL UPDATES THAT THE OS IS PROMPTING TO DOWNLOAD. AT EACH AND EVERY UPDATE, THEERROR IS BEING SHOWN.
2. CHECKING SYSTEM REQUIREMENTS. EVERYTHING IS FINE,MY PC IS READY FOR WINDOWS 8.1.
3. TRYING VARIOUS TROUBLESHOOTERS FROM THE ORIGINAL WEBSITE [http://windows.microsoft.com/en-US/windows-8/why-can-t-find-update-store].

I HAVE TRIED EVERYTHING LITERALLY PLEASE HELP AND ACKNOWLEDGE FOR THE SAME.