I had Windows 8.1 and i was booting using UEFI. I installed Ubuntu 13.10 in Legacy BIOS and than i was trying to convert it in EFI using this: https://help.ubuntu.com/community/UEFI
Converting Ubuntu into EFI mode Start Boot-Repair, click on "Advanced options", go to the "GRUB location" tab. If you do not see a "Separate /boot/efi partition" line, this means that your PC does not have any EFI partition. In this case, exit Boot-Repair, then create an EFI partition (see the "Creating an EFI partition" paragraph above). If you see a "Separate /boot/efi partition" line, tick it then click the "Apply" button. Set up your BIOS so that it boots the HDD in EFI mode (see the ""Set up the BIOS in EFI or Legacy mode" paragraph above).
Now i want to restore Windows 8.1 booting in UEFI again but when i switch to UEFI in BIOS i get "NO OPERATORING SYSTEM"
I also have a recovery partition if that helps.
Can anyone help me restore Windows MBR again booting in UEFI ?