Pre - boot system preformence check happened out of nowhere and I don't know what to do

My laptop randomly made a loud beeping noise and then opened a screen that says "Dell support assist I Pre-boot system preformence check" and then it started doing some kind of test but when the test was finally finished it said "Pre-boot system preformence check 2.49 - success" "no bootable devices were found! Possible causes could be a corrupt OS image or a boot device is not enabled in BIOS setup" with a button that says "shutdown" in the middle, I don't want to click anything because I have no idea what this is and I'm aftiad I might break something, please help