Desktop window log out before open it

few day before, i was unable to open desktop window on PC. I have tried any answer form Math Work, but still failed. than i decided to reinstall the computer and installed again. After installed desktop window, i logged my friend's account (cause i can't recive the verify mail). Everything is down.

here is the problem

if my desktop window can open is system promblem, which is easy to slove.

What if the problem is the account verify fail cause desktop window don't show up. How to log out my account before open Matlab desktop window ?