Linksys Wireless Router :: WRT54G Connecting To Wireless Network?

I've been having a ton of problems with fixing my connection with my wireless network.  A few months ago, I lost connection on my desktop computer and I reconnected... however, it didn't actually connect.  When I hovered my cursor over the Wireless Network Connection icon, it just said "Acquiring Network Address" and never connected.  I got onto my laptop and did a quick search on the problem.  A few wrong moves later, and I couldn't even find my wireless network.
 
Despite all of my attempts at creating a connection, I still have no internet.  I've even tried plugging my computer into my WRT54G router via cable, and still no connection.  It's not the router that's the problem, though, as my two other computers and xbox have perfect internet connection. 
 
I use Windows XP, I use a WRT54G router, I have Mediacom high speed internet, and that's about all I know.