Computer will not boot, trying too remove ubuntu partition

[bearcat]

I followed this
The Non-Geeks Guide To Safely Uninstall Ubuntu From A Dual-Booting Machine

And when I restarted my PC, after following the instructions, I'm now only getting a black screen with a blinking underscore. Also I'm totally unable to open the disk drive.

 

[Pillars of Creation]

What is the other operating system that you have installed on the computer?