dnetc is the name of the current distributed.net client. dnetc is a console application under Unixes, and runs in its own little terminal emulator window under Windows.
The client is massively configurable with regard to performance (you can choose which computation core to run), network load and logging.
You can even point it to a proxy for running in very paranoid firewalled environments.
Remember to download dnetc from a trusted server, like the ones at distributed.net. Especially on a Windows 95 (or 98) system, you are trusting all your system integrity to any executable you decide to run.
Tip: if you want to load a whole Windows lab with dnetc, and you don't want the people to mess with it, choose the "detach" option in the configuration. Of course, you will not get the cute cow icon, but everything has a price.