A user reports that their Windows 10 computer has become unresponsive and problematic after a recent update was applied. They are experiencing frequent crashes and the 'Restore' function has not resolved the issue. They cannot afford to lose their applications or personal data. What is the BEST step to take next to troubleshoot this issue?
Run the 'Deployment Image Servicing and Management' (DISM) tool to restore system health and reattempt updates.
Start the computer in 'Safe mode' and attempt to troubleshoot individual services and applications.
Perform a repair upgrade by running the Windows installation media from within the OS and choosing the upgrade option.
Use the 'System file check' (SFC) utility to repair system files and then reboot the computer.