Wireless Network Missing Entirely From Laptop?

My Dell Inspiron windows 7 laptop's wireless functionality has completely stopped working. Instead of a wireless tray icon, in the bottom right, there is a broadband ethernet icon, with a red x. There is a button on the keyboard which enables wireless, but pressing that has stopped doing anything. Troubleshooting the problem, it tells me that I need to connect an ethernet cable, for it to work.Checking the network connections page, there is no wireless driver or connection listed. Only the broadband. In short, my wireless driver is completely gone.I've tried downloading drivers from the manufacturors website, but there is none.