Firstly, you need to boot from a Windows 8 installation Disk or USB. At the installation screen, just click on the button Repair on the left corner.
- You will need to choose the language and time settings.
- Choose 'Repair Your Computer'.
- Choose 'Troubleshooting'.
- Choose "Advanced Options'.
- Next choose 'Command Prompt'.
Now type 'DISKPART' (Enter)
Then type "sel disk 0" (Disk0 is my personal scenario, you can change to yours)
Disk 0 is now the selected disk.
Then type "list vol"
There was no drive letter assignment to our UEFI partition (volume 3) so we need to assign a drive letter.
Then type "sel vol 3"
Volume 3 is the selected volume.
Then type "assign letter=Z:"
DiskPart successfully assigned the drive letter or mount point.
Exit DiskPart tool
Change to the UEFI volume into the boot folder. Depending on the way Windows was installed this path maybe one of the following.
cd /d Z:\Boot\
cd /d Z:\EFI\Microsoft\Boot\
cd /d Z:\ESD\Windows\EFI\Microsoft\Boot\
Now we will need to enter three command lines to repair the BCD store.
- bootrec /fixboot
- bootrec /fixmbr
- bootrec /rebuildmbr