Boot manager repair

Windows boot manager javítása

Backup Before Attempting This!

Step 1: Delete old partitions and create new ones

• Boot into your partition manager of choice (I used Parted Magic https://partedmagic.com/ ) GParted
• Delete extra partitions including the old FAT32 system partition (These all should be very small between 100 MB and up to 2 GB)
• Create new NTFS partition with 512 MB of space and label it System Reserved
• Shutdown

Step 2: Setup Partitions with the correct drive letters

• Launch Windows 10 Install disc / usb
• Shift+F10 once you see language select to bring up command prompt
• Launch DISKPART
• select volume with 512MB (ex: select vol 0)
• assign letter=G: (or any letter that isn’t taken that is NOT C:)
• exit OR If Windows operating system is NOT on C:
• select volume with windows installation on it
• assign letter=C:
• exit

Example output:

diskpart
select disk 0
list vol
select vol 0 <---500 MB Partition
assign letter=G:
select vol 1 <--- Large Partition with Windows Install on it
assign letter=C:
exit

Partitions are done. Now time to fix problems with the “type” of partition – By forcing all partitions to be NTFS NT60

bootsect.exe /nt60 all /force

Step 3: Copy Boot Records, Fix MBR, and Rebuild BCD

Rebuild new system reserved partition with EFI and regular boot files

bcdboot c:\Windows /s <boot letter of System Reserved Partion>: /f ALL
bcdboot c:\Windows /s G: /f ALL

• Now we can finally rebuild the bcd and master boot record like you see in so many online guides
• You can verify the system is seeing the windows installation by doing a bootrec /scanos and then be running through the rest of the commands to do the rest of the repairs

bootrec /scanos <---Verify it sees the windows install
bootrec /fixmbr
bootrec /fixboot <----Pick the installation will mirror /scanos bootrec /rebuildbc