Recover windows 10 EFI Boot from dual boot with ubuntu

I made my window 10 system system in dual boot with ubuntu. I would like to remove ubuntu and install it in virtual-box within windows.

I am afraid to remove ubuntu partions fearing windows may not boot after it. Currently I get ubuntu Grub screen on booting computer. How do I get my windows bootloader back so that I don't see grub screen again. Once I am able to do that I can delete ubuntu partions and merge it back with windows partitions.

Please help to get me my windows bootloader back.

Thanks :)

You only need to delete the EFI binaries of grub from the ESP ($ESP/EFI/grub/grubx64.efi and/or remove the EFI boot entry of grub with efibootmgr -B. The Windows Boot Manager should not have been touched by Ubuntu ($ESP/EFI/Microsoft/bootmgfw.efi) and it is discovered automatically by most UEFI (so you don't need to register it manually; efibootmgr should tell whether there's an existing entry for it as well).

($ESP is the mountpoint of the EFI System Partition, e.g. /boot/efi)