Have you set up the router at your office to be the vpn endpoint? If you've just set up both sides to do passthrough, you need to have a vpn server on one end. In your case, it sounds like you'd need ...

I'm looking at setting up multiple machines to connect to my University via PPTP. The machines in question are behind a Linksys router, and I'm curious as to whether or not anyone has a good idea as ...