Tips and tricks

if the boot sector is damaged, or Windows does not boot
if you installed Windows after another OS, you might not have the EFI folder.
So I installed GParted on a portable usb memory
Shrinked the main windows partition, and created a EFI Partition
make a windows recovery usb memory
diskpart
list disk
select your diskselect disk 0
list partition
if you need to delete a partition:
select the parition you want to delete
select partition 3
delete partition override
just to be sure, list and reselect your diskcreate partition efi size=100
format quick fs=fat32 label="System"
assign an unused letter (ex: A,B,K,G,…) for the next stepassign letter=A
exit
“fill with stuff to make it boot”
taken from http://woshub.com/how-to-repair-uefi-bootloader-in-windows-8
make directory
mkdir A:\EFI\Microsoft\Boot
cd into it:
A:
cd efi\mic*
cd boot
OR
cd /d A:\efi\microsoft\boot
your Windows volume should be C:
, if not, change the letter or assign letter
bcdboot C:\Windows /s a: /f UEFI /v
- a: is installation target
- C:\Windows – is the path to the directory with Windows 10 installed;
- /f ALL – means that you want to copy the Windows Boot Environment files, including those for UEFI and BIOS computers (potential ability to boot in UEFI and BIOS systems). To copy only the EFI bootloader, use the /f UEFI command;
- /l en-us — is a type of the system locale. By default, en-us – English (USA) is used;
- /c – this is a new BCDBoot option in Windows 10 that allows you to overwrite existing boot records (including debugsettings). Use this option to ignore old boot settings and create a clean BCD configuration;
- /v – used to enable BCDBoot verbose output.
if it says successful, you may now reboot
else, read here for errors http://woshub.com/how-to-repair-uefi-bootloader-in-windows-8