The MBR, or Master Boot Record, is created when you first install Windows. The first 512 bytes of the hard disk are allocated for it. If this entry is damaged, Windows will not start. All versions of Windows: Windows XP, Vista, 7, 8, 10 – use MBR and if they are damaged you will not be able to boot.
- Corrupted by malware viruses that target the boot sector to replace it with their own code.
- The boot sector is damaged (physically). Unlikely.
One example of an error message. The text differs depending on many factors. Example:
- Reboot and select proper boot device;
- No bootable medium found;
- Invalid partition table;
- Operating System not found.
The easiest way to fix it is to download
… Follow the instructions and the program will fix the problem automatically.
Below we will consider a solution to this problem that will fit all OS versions.
Fixing MBR errors
To fix the MBR, you need the original Windows 10 installation DVD media.
- Boot from the original installation DVD (or USB recovery).
- On the welcome screen, click Repair Your Computer.
- Select Troubleshoot.
- Select Command Prompt.
- When loading the command line, enter the following commands (press Enter after the next one):
bootrec / FixMbr bootrec / FixBoot bootrec / ScanOs bootrec / RebuildBcd
- Then disconnect the media with the installation version of Windows.
- Reboot and check if Windows boots.
If that doesn’t fix Windows, follow these instructions.
- Follow the previous steps 1 through 4.
- Now enter other commands:
diskpart sel disk 0 list vol
These commands will select the first drive on the computer and a list of all partitions available on that drive.
- Check the volume element that the Fs column has. The EFI partition must be formatted with FAT32. If the volume number of the partition is “2”, enter the following:
sel vol 2
If the volume number is different from 2, replace “2” with a number not already in use.
- Assign a letter to this section that is different from the one already used on your computer. For example “x:”. Enter this command:
assign letter = x:
- Wait for successful completion.
- Type “exit”.
cd / d x: EFIMicrosoftBoot
Remember to replace x: with the letter you assigned to the EFI partition.
- To check the volume, write:
bootrec / fixboot
- Let’s create a backup:
ren BCD BCD.backup
- Here we change the x: to your letter, as before:
bcdboot c: Windows / l en-us / s x: / f ALL
Note: Cdisk indicates where your OS is installed, if it is located in a different place, change the disk.
- “Exit” -> reboot.