Installation troubles

So I recently built my first computer, and I was so excited it was going great, I installed all my drivers, and downloaded some of the software, steam, itunes etc. Anyway I will try to break this down to make this easier to follow
-I stepped away while it was downloading LoL
-I came back to see a screen saying Windows could not repair this computer automatically
-I performed some of the options, reverting to an earlier state, and even using the repair tool on windows itself
-I then attempted to reinstall windows entirely, and I would just move some key files over from the Windows.old file
-Instead my computer asked me to select which windows I wanted to run, after trying them both neither worked
-after surfing the internet I didn't find a lot of help, so I used the command prompt to clear my hard drive, I had figured I would just have to reinstall a few drivers and download some stuff no big deal
-but instead my computer still prompts me to select one of two windows to run, again neither working
-now installing off of the disk doesn't even finish

All I want is to start fresh any thoughts on clearing the two useless OS?