#Active boot disk registration key windows

Therefore, when you run bootrec commands, you will see an error: access is denied If your computer boots in UEFI mode, then it definitely uses the GPT partition table (as in our case). You can use all these commands only for MBR-based disks.

#Active boot disk registration key windows

In our example, the main partition on which Windows is installed has a volume 2 index, is formatted in the NTFS file system, and is assigned the drive letter C.Īt this point, many guides recommend running the following commands, which should overwrite the partition boot record, find the installed Windows, and add them to the BCD:īootrec /FixMbr (preparing MBR record for a GPT disk looks strang) The most commonly used label for it is System EFI or ESP/EFI System Partition). The easiest way to identify an EFI partition is by the FAT32 file system and 100 MB in size (this is the standard minimum size of EFI partition for Windows computers in rare cases, the partition size may differ). In this example, you can see that the EFI boot partition has the partition 2 index (aka Volume 5 with the Hidden label). Select the drive where your Windows is installed (if there is only one hard drive in the system, its index should be 0):ĭisplay the list of partitions and volumes on this disk: list partition Use another guide to restore the BCD bootloader on a BIOS computer with MBR (Master Boot Record) disk. On MBR disks, the Windows bootloader is stored on a separate System Reserved partition, and not on the EFI partition (in any case, don’t convert the MBR partition table to GPT until you fix the Windows bootloader !!). After booting into the recovery environment, you need to open a command-line console: select System Restore – > Troubleshoot-> Command Prompt). To repair the bootloader configuration (BCD), you have to boot from the original Windows installation media (also, you can use a recovery disk or a special UEFI bootable USB flash drive). Let’s move on to the procedure for manually repairing the EFI Windows bootloader on a UEFI computer. Using BCDBoot to Manually Repair EFI Bootloader in Windows But most likely the result will be negative: Automatic Repair couldn’t repair your PC.Then select Troubleshoot -> Startup Repair and select the OS whose bootloader you want to try to repair.Click the Restore System on the installation screen.Boot your device from the recovery disc or Windows 10/11 installation media.The procedure for the automatic repair of the EFI bootloader used in the Windows Recovery Environment (WinRE) is usually useless in such cases. Automatic Windows Bootloader Repair with WinRE If you only see a black screen with the message “An operating system wasn’t found” when you boot your computer, it’s likely that the Windows bootloader has been completely removed.