Restarting your computer in repair mode, also known as Windows Recovery Environment (WinRE), can help fix common startup problems. To access repair mode, you'll need to initiate a restart and then enter the boot options menu, usually by pressing F8 or Shift + F8 as the computer starts up. If this doesn't work due to fast startup times, you can also access WinRE from within Windows by navigating to Settings > Update & Security > Recovery, and under Advanced startup, click 'Restart now'. Once in WinRE, you can use various tools like 'Startup Repair' to diagnose and fix issues.