Bootrec Fixes Win10 Boot Problems
For those who regularly install, upgrade, update or repair Windows 10 installations, the occasional boot problem is inevitable. When such things occur, don’t panic. Turn to your trusty repair kit instead. And fortunately, the basic Win10 install media — and the vast majority of bootable repair, recovery and rescue media — includes command line access as part and parcel of WinRE. That’s the Windows Recovery Environment fully expanded, which looks like the following screenshot when booted into. Accessing that (or similar) environments provides access to the command line, and is where Bootrec fixes Win10 boot problems.
You need to get to the Troubleshoot options to start dealing with boot-up issues or problems in Win10.
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Hang in there: the command prompt appears beneath the “Advanced options” item here.
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Both Startup Repair and the Command Prompt offer potential relief.
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Getting to Where Bootrec Fixes Win10 Boot Problems
Once you see the options that read “Startup Repair” and “Command Prompt” you’ve now got tools at your immediate disposal. There’s nothing wrong with clicking “Startup Repair,” but it’s important to understand it doesn’t always work. When you next attempt to boot Windows (it runs automatically), your error may repeat. If that happens, step through the same sequence again, but choose “Command Prompt” instead. That’s where you’ll make direct acquaintance with the bootrec command. (It’s covered in great detail in the Microsoft support article “Use Bootrec.exe in the Windows RE to troubleshoot startup issues“.)
Bootrec.exe supports the following options (listed here in alphabetical order):
/Fixboot: writes a new boot sector to the system partition using a boot sector compatible with Windows 10. Use this option when a boot sector has been replaced with a non-Win10 boot sector (as when dual- or multi-booting older Windows versions or non-Windows OSes), or when the boot sector is damaged or missing
/FixMbr: writes a Windows 10-compatible Master Boot Record (MBR) to the system partition. Does not overwrite an existing partition table. Use this to fix MBR corruption, or to remove nonstandard code from the MBR.
/RebuildBcd: Scans all disks for installations compatible with Windows 10 (and earlier Windows versions). Lets you select installation you may wish to add the Boot Configuration Data (BCD) store. Use this option to completely rebuild and replace an existing BCD store. See the MS support article for details on addressing the “Bootmgr Is Missing” error message that you may sometimes encounter.
/ScanOs: Scans all disks for installations compatible with Windows 10 (and earlier Windows versions back to Vista). Use this option to show Windows installations that the boot manager menu omits or skips over (and to check for a valid Windows installation on the system disk).
[Note: This NeoSmart article offers additional bootrec information and insights, especially for Windows 10: “bootrec — Guide for Windows XP, Vista, 7, 8, 8.1, 10.” Be sure to check it out, if you’d like more information on this great command and its options. Their troubleshooting section is especially informative.]