Net will work with any computer with an Internet connection. Using scheduled tasks, you can even set up the Client application to automatically launch at night or when the machine goes to sleep. This is a screenshot of the Web interface connected to the server showing what Clients are connected and what it is that they are rendering. The Client software included with C4D Net can be freely distributed to the machines that will be rendering for you. Before you think this is a perfect setup, it's important to realize that there are indeed some drawbacks.
Net is fairly picky about how files are named and what format they are in.
For instance, C4D Net does not like textures that are built from QuickTime or AVI movies. Net doesn't like working with .pict files either. Further, if you use special plug-ins, C4D Net will not automatically forward those to Client machines. Here's an example of the flexibility this package lends. In my office in San Antonio is an NT machine that acts as the Server.