If your computer refuses to boot or displays errors like "Operating System not found," a damaged Master Boot Record (MBR) is often the culprit. You can fix this using built-in Windows tools or dedicated third-party software.
bootrec /fixboot — Writes a new boot sector to the partition. Hard Drive Mbr Repair Software
: Type these commands in order, pressing Enter after each: If your computer refuses to boot or displays
: Select Repair your computer > Troubleshoot > Advanced options > Command Prompt . Hard Drive Mbr Repair Software
bootrec /fixmbr — Writes a new Windows-compatible MBR to the system partition.