Repair the EFI Bootloader or the MBR (Master Boot Record) for …
Launch Command Prompt. Step 2. Use Command Prompt to fix issues with your PC's boot records. Once you've started Command Prompt on your problem computer, you can use some advanced tools in it to repair the boot records. Read the next section to see how to repair the EFI Bootloader on a computer with UEFI and GPT drives …