The Problem

The Solution without any media

Open Command Prompt

Open Command prompt, if automatic repair doesnt fix.

Open diskpart

Type and run the command:

diskpart

Select Hard Disk

Type and run the command:

list DISK
sel disk 0

Check the partitions

Type and run the command:

list vol

Select EFI partition

The EFI partition should be using the FAT32 file system. It is around 100 MB. Assign a drive letter to it that is not already in use:

Type and run the command:

sel vol <number of volume>

assign letter=<drive letter>:

exit

Repair the boot record:

Type and run the command:

cd /d <drive letter>:\EFI\Microsoft\Boot\

bootrec /FixBoot

If you have access denied then do the following:

bcdboot C:\windows /s <drive letter>