Step 3. Use fdisk -l to see the name of your stoage device.
one of this will be EFI/System volume, it will always in FAT32 format 5.
/dev/sdaXY]> <mount-point [e.
From Type choose Linux (GRUB) or (GRUB 2) c.
troubleshoot> advanced options> startup repair.
Now you need to launch Boot-Repair by typing boot-repair in a terminal.
Load the module to the kernel by executing the command “ insmod normal ”.
type diskpart in cmd window and click yes when prompted.
Assuming you only ever had two operating systems (Win 10 & Ubuntu) you should now be able to boot directly to Windows without hitting the black grub screen.