Before proceeding, please note that downloading Windows 8 Build 7850 ISO might require some technical expertise and caution. Since this build is no longer officially supported by Microsoft, you won't find it on their official website. However, you can still find it on some third-party websites that specialize in hosting old software and operating system builds.

A full-screen application designed for the then-conceptual "Start Screen". Where to Download Build 7850 ISO

Pre-release versions of the "Modern" apps we see today.