Error installing on Windows 7

You are building a quite outdated fork of Panda, so you might have more luck opening an issue there to ask them to merge from the official Panda3D repository. It may be that the problem has already been solved.

Furthermore, you didn’t actually post the error message. (This is just makepanda telling you which command gave the error message, not the error message itself.) We would need the whole build log to be able to help you.