I had a hard disk with 2 partitions.
On the first partition there was a clean Windows 7 install.
The second partition was empty but formatted to NTFS.
I tried to install Ubuntu, using the Along side Windows 7 option, leaving everything at default.
At reboot the GRUB bootloader showed up. It would let me boot into Ubuntu, but when I chose to boot Windows 7 it just returned me to the bootloader menu.
I tried reverting back to the Windows bootloader by loading a Windows8 DVD and using the command prompt with:
This broke everything. The bootloader doesn't show up and there is only a black screen with a flashing cursor. All I can do is Ctrl+Alt+Del to restart.
After this I've deleted all the Ubuntu partitions and grew the Windows partition back to full disk size.
The Windows 7 automatic repair tells me there is nothing wrong.
I've executed all the steps on this site: https://neosmart.net/wiki/display/EBCD/Recovering+the+Windows+Bootloader+from+the+DVD with no effect.
All my files on the disk are intact, I just cannot get into Windows. I think I've tried everything there is, but I get no results except a blinking cursor.
What causes this and how can it be fixed?