How do I change default installation paths?

I built a new machine, and part of that included that I took a 40GB SSD from my old machine, formatted it, and made it just for Windows. The problem is, everything tries to write to it automatically; I want everything to write to a different drive. I figured out how to change registry values with the link at the end of this post, but I don't know how to change it for everything else.

Anyone have any suggestions?

http://www.ehow.com/how_7628549_change-default-installation-drive.html