Pip should be installed when you create the virtual environment. Don't change directory into C:\Python33\Scripts before running pip. It looks like that means you use the base install's pip instead of your virtual environment's pip.
You should be able to run pip from any other directory. However I'm not familiar with python on Windows, so I'm not certain that pip is added to the path when you activate the environment. If that doesn't work, you'll have to change directory into the bin directory of your virtual environment, then run pip.