Hi

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The Broadcom is your onboard ethernet port.
IE 1394 is a firewire connection for ethernet.
The wireless is self-explanatory

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The Broadcom port will not work until the appropriate driver for it is installed. The drivers for it should be obtainable from your drivers CD which came with your system...or as a download for your specific system from the website of Dell.
Once that driver is properly installed, you should be able to continue your wireless setup.
Louis