Windows Bootloader

Documentation

install docs

https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/windows-setup-installing-using-the-mbr-or-gpt-partition-style

Tutorials

replace win10 bootloader	http://woshub.com/how-to-repair-deleted-efi-partition-in-windows-7/
anatomy of windows bootloader	https://superuser.com/questions/308823/where-does-the-boot-loader-reside
how to repair bootloader	https://superuser.com/questions/949219/how-to-fix-the-windows-10-boot-loader-from-windows

Installing Windows

To install as with UEFI bootloader, you must load install-media with UEFI.
Otherwise, only MBR will be available.

You can tell which will be installed by:

• 2x partitions(MBR) (recovery, OS)
• 4x partitions(UEFI) (recovery, EFI, MSR, OS)

install/repair bootmanager

create EFI partition (linux)

sudo fdisk /dev/sda
g  # create GPT table
w  # write

sudo fdisk /dev/sda
n      # add partition
       # default num
+100M  # windows EFI is large
t      # change partition type
{}     # choose partition num
4      # 'BIOS boot' partition
w      # write changes

sudo mkfs.msdos -F 32 /dev/sda{X}

mount EFI partition

diskpart
#> list disk
#> sel disk 2
#> list vol
#> sel vol 4
#> assign letter=G
#> exit

clean/reinstall bootloader

bcdboot /bsdclean                 # remove duplicates
bcdboot C:\Windows /s G /f UEFI   # install bootloader (UEFI) (where G is EFI partition)

# on reboot, you may need to run this if recovery options are not present
reagentc /info