: Insert your Windows installation USB/DVD and boot from it.
bootrec /fixmbr — Writes a new Windows-compatible MBR to the system partition.
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. Hard Drive Mbr Repair Software
bootrec /rebuildbcd — Scans for installations and rebuilds the Boot Configuration Data. How Do I Fix the Master Boot Record (MBR)?
This is the most direct method and doesn't require downloading extra software if you have a Windows installation or recovery USB. : Insert your Windows installation USB/DVD and boot from it
: Select Repair your computer > Troubleshoot > Advanced options > Command Prompt .
: Type these commands in order, pressing Enter after each: You can fix this using built-in Windows tools
bootrec /fixboot — Writes a new boot sector to the partition.
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