When I run cmd.exe, how do I get type unix commands such as 'ls', and 'pwd' to work? Is there a way I can get this to work without installing other software?
I think it's impossible without installing additional software.
Anyway, if you accept to install additional software, this is exactly what you are looking for:
A large collection of GNU and Open Source tools which provide functionality similar to a Linux distribution on Windows.
A DLL (cygwin1.dll) which provides substantial POSIX API functionality.