Triplej,
For that many PCs if they are all on the same network, You can run a personal proxy on on of the PCs that has an Internet connection, and the proxy can fetch/flush blocks for all of the other PCs. This not only reduces network traffic, but you can buffer enough WUs to last for several days in case the Internet connection is down, or dnet has problems. Plus there are stats proggies you can use to see the stats of each PC. Some people use them to help monitor the network.
The DNET.SCR is a screen saver version, if you are running the client installed as a service you don't need it. The client will use the dnetc.ini file, and will only overwrite it if you run the dnetc -config or modify the .INI file yourself.
What I did was create a folder on a network drive accessable from all PCs that contains DNETC.EXE, DNETC.INI (configured the way I want), and a number of BAT files (or shortcuts) with some of the CLI commands, such as
DNETC -INSTALL
DNETC -SVCSTART
DNETC -FLUSH
DNETC -FETCH
DNETC -SHUTDOWN
DNETC -UNINSTALL
Then I just copy that folder to the PC, execute the DNETC -INSTALL shortcut, the DNETC -SVCSTART shortcut, watch for it to create the BUFF-IN.RC5 and BUFF-OUT.RC5 files, the ckpoint file, and the log file.