Networking & wireless: NICs all missing icons, no more network connection

NICs all missing icons, no more network connection

The computer system:

CPU: AMD Athlon 64 FX-62 Windsor 2.8GHz (Socket AM2)
RAM: G.SKILL 2GB 240-Pin DDR2800 PC26400 (two sticks. 4GB total)
GPU: EVGA GeForce 8800GT 512MB PCI Express 2.0 x16 Superclocked
Mobo: ASUS M2N32-SLI Deluxe Wireless Edition AM2 NVIDIA nForce 590 SLI
OS: Microsoft Windows XP Professional 32-Bit SP2 (with all the latest required updates, so technically SP3, though not "officially")
NICs: nVidia 590 chipset built into the motherboard
Router: Linksys Broadband A+G Wireless w/ 4 ethernet ports
Preferred interface: Wired ethernet (not wireless)

The story:

I was playing WoW (haha, first problem, j/k) and there has been some strange issue with the newest patch (2.4.x) where some user's computers would hang upon exit. The music changes to the character select music and the graphics freeze. The mouse is still movable, but nothing can be clicked. Alt+Tab does not work to switch to another program or Explorer, Alt+F4 doesn't work to close WoW, and Ctrl+Alt+Del doesn't even work to bring up the Task Manager or soft reboot. In fact, nothing on the keyboard works when the system hangs like this, not even the notorious Windows key.

The only way to get past this is to do a hard reboot. And I've had to do this a few times whenever the system would hang as a result of the said WoW issue. But this time was different. This time after reboot, I couldn't connect to the internet with Firefox (or anything else). I checked my firewall and my IP was listed as 0.0.0.0 with nothing going upstream or downstream.

I thought it was a router or modem issue, so I reset both my router and my cable modem. I was wrong, as the other computers connected to the router were still able to connect to the internet, but mine still could not. I checked the Device Manager and it lists all of my NICs as being enabled and "working properly". I checked Network Connections Properties and there were no icons or text, when it would normally list "LAN or High-Speed Internet" with my connections, and "Wizard" with the New Connection Wizard and Network Setup Wizard. But no, not anymore; nothing here.

Slightly panicked, I did everything I could think of:

-Adjusting the ethernet cable
-Turning off firewalls
-Roll back to another restore point with System Restore
-Uninstall/auto-reinstall all of the NIC drivers
-Manually install the nVidia drivers from the ASUS motherboard disk
-researched the issue online with another computer and even followed this article on support.windows.com: http://support.microsoft.com/kb/825826

Even after completing almost all of the steps in the article above, this problem is still unresolved! Please help, and please be specific!

Thanks, everyone.