I know its not the mac because I have other virtual machines on there which are all working fine. The windows networking control panel is a disaster. It never can find anything wrong and at the end of it all, it suggest - "Ask a friend for help using remote assistance."
This is a fucking ridiculous suggestion considering the problem is that I don't have an internet connection.

I tried searching for all kinds of combinations of issues with OS X host virtualbox and windows 7 client to no avail. The one thing I noticed was that the windows machine had a default route of 0.0.0.0 and it could reach the router but not the internet. When I would ping something it could get the correct address from the router, but then no response. So I started searching for how to change the route on windows which lead me to the solution. Turns out that Adobe Creative Suite 3 installs some bunk bonjour discovery service that wrecks windows 7 networking. It had nothing to do with Virtualbox itself and would have happened on a real windows 7 machine.
The real problem is that the solution actually turned out to be so obscure, non-intuitive and definitely complicated. I would like to point out that things do not just work in windows and that at least on a non-windows system I could much more easily debug the issue. I have no idea how someone would have debugged this without an internet connection and I clearly had a hard time even though I am an advanced computer user, meaning that I at least knew which terms to look up. Seriously, a regular windows user would have no idea what a route was.
Check out how obscure the solution was:

This whole process took me several hours as I tried so many combinations of virtual box settings, drivers, installing other guest OSes to make sure it wasn't just a virtual box issue - all before getting to the real problem. Now that its working I made a snapshot for (e:Terry) to roll back to, next time Windows 7 gets fucked up.
Sure I could show you. Do you have iTunes. I read that it installation a newer version of bonjour which can also solve the problem.
Thanks for fixing it. Windows sucks and I'm sorry it was such a pain. I've installed CS3 on at least four boxes, including Win7, and not had any problem. :-p Would you mind spending a few minutes sometime to give me an intro to the virtual machine?