Please note that this fix ONLY works if the hard drive has an MBR partition table.
How to determine if a hard drive is configured with the MBR or GPT partition table (see screenshots below).
Note that bootrec /fixmbr and bootrec /fixboot commands are not needed at all, if the hard drive has a GPT partition table. UEFI boot mode do not use boot sectors on the hard drive and do not require active partition to be set.
How to fix the Windows 7/8/8.1/10 bootloader if the hard drive has an MBR (Master Boot Record) partition table.
For example, if you have deleted the System Reserved partition and then you get an error message "Operating System not found".
Note that these instructions does not wipe the hard drive.
- Boot the computer using the Windows 7/8/8.1/10 installation media.
- On the first screen, press SHIFT+F10 to bring up the command prompt.
- Run the following commands at the command prompt.
bootrec /fixmbr (writes a MBR to the system partition but does not overwrite the existing partition table)
bootrec /fixboot (writes a new boot sector to the system partition)
The bootrec /rebuildbcd command will search for Windows installations not included in the Boot Configuration Data (BCD) and then ask you if you'd like to add one or more to it.
If you receive the error message "Element not found" when you execute the bootrec /fixboot or bootrec /rebuildbcd command, then you must first mark system partition as active with diskpart. Note: If there is a partition labeled "System Reserved", it is the system partition, if not, the Windows OS partition is the system partition.
select disk 0
select partition # Note: Select the "System Reserved" partition (if you have it) or the Windows OS partition.
If Windows still does not start and you receive the error message "BOOTMGR is missing", then copy the bootmgr file from the Windows installation media to your Windows OS partition root directory.
If you have deleted the System Reserved partition in Windows 7, this error message should appear. But if you have deleted the System Reserved partition in Windows 8/8.1/10, this error message should not appear, since the bootmgr file should already exist on the Windows OS partition.
list volume Note: Note the volume letters.
(these instructions assume your installation media drive is D: and your Windows OS is installed in C: drive)
copy D:\bootmgr C:\
- How to create a bootable Windows 10 USB flash drive or DVD. -> link
- How to download and clean install Windows 8.1 -> link