DistributionNotFound error after upgrading pip

Question

In reading about virtualenv here I realized I didn\'t have pip 1.3+, so I ran pip install --upgrade pip and now when I run pip --version i get the

Answer 1

I wanna find out at where pip 1.2.1 is required, but I don't have so much time... so I just downgrade pip to 1.2.1. It can't be helped for a while, till pip or distribute package is modified.

How to do this? just type this in console(I hope your distribute package is well):

easy_install pip==1.2.1