I'm new to Linux so I switched to zorin os but for some reason it started to slow down so I decided to again reset it from my bootable pendrive and it got successfully installed asked me to restart but after reboot it started showing this error. I have surfed through internet bu haven't found a solution yet to fix my issue all that I found were possible when I had dual boot either Windows or another Linux. But I just don't have any dualboot. Plz help friends.