after having to switch back and forth manually, i found this freeware that allows one to switch between network settings. Net Profiles
works on a profile basis, basically create a profile and key-in a set of values pertaining to the network that you want to be connected. among the options you can alter with a profile are IP addresses (dhcp or manual), proxy settings, default browser homepage, mapped drives, screen resolution, wallpapers and even activate Wireless SSID based on different profiles.
With Net Profiles, mobile computing becomes a whole lot easier. It eliminates the need to manually reconfigure your network settings when you move your desktop/laptop computer to another location. Once a profile is created, Net Profiles can configure your IP settings, proxy settings, mapped drives, default printer, wallpaper, and screen resolution with a click of a button; as well as run any number of user-defined applications upon activation of a profile.
in the changelog there is a note saying, "Completely rewritten in .NET 2.0" so .NET 2.0 runtime might be needed but i can't verify since i already have .NET 3.5 on my system.