None of the above fixed my problem.
I added "C:/Windows/System32" to the 'Path' or 'PATH' environment variable. I could use the reg /?
command. I also ran the 'vcvarsall.bat' file with no error message.
My error is that I was running VS2012 Cross Tools Command Prompt instead of VS2013 Cross Tools Command Prompt.
The reason being the file structure in the start menu. 2010 and 2012 are under 'Microsoft Visual Studio YEAR' and 2013 is under 'Visual Studio YEAR'. I just didn't realize this. :/
I hope this helps someone.