Okay, this really isn't completely related to the question at hand, but more related to one reason why the question was originally asked.
If you're using ndiswrapper for your wireless card, when you upgraded to FC4 you lost that functionality temporarily because FC4 included a kernel upgrade. You'll have to download the ndiswrapper source, unpack it, make distclean / make / make install, modprobe ndiswrapper, and ndiswrapper -m.
Then check to make sure the drivers are recognized with ndiswrapper -l. Stop and restart the network services, and you should be good to go.
But then, if you're not using ndiswrapper, ignore everything I just said.