I changed the battery after getting a low batter warning.  I updated BIOS with the date and time.  I am unable to get to Windows 10 operating system.  I pressed F12 from the Dell screen to run diagnostics.  The diagnostics stops when it begins running the MATS test.  I tried this twice. It stopped each time at a different CPU address.  The computer locked up and pressing ESC to abort wouldn't work so I had to turn it off be holding down the start button.  How to I fix?