cant get rid of dell supportassist pre-boot system performance check vostro 3590

i tried multiple solutions and nothing worked. i wanted to factory restart the laptop with support assistant and it said it failed after that it started to show me pre boot system performance check in a loop cant connect it to the wifi either bc its wireless. after a while it showed me that i have no bootable devices i tried to create a new boot as “windows boot enable” didnt work either and i dont know if even a technician can solve it or not im trying to solve it at home without going anywhere but if i cant i would prob go to one