My Network adapter cannot be found?

Hi Everyone I am having problems with my Dell XPS 8300 desktop computer, which runs on Windows 7 and has a 64bit operating system. The problem might have something to do with the *network adapter* as when I turn on the computer the network icon in the bottom right corner of the screen is marked with a red cross. I connect to the internet using an *EchoLife HG520s* Broadband Wireless...