So i had put a 3.1 update on someone else's Calculator but he somehow screwed around and deleted the OS somehow and now i cant install any os at all saying error installing os (At the end of the installation.) It now just rests on OS not found, install OS now.

Everytime i install 3.1 again it says update succesfully send with the student software and the calculator says error installing OS, and reboots into the error screen again.