Unable to connect to internet on only 1 computer

I have 3 desktops and 2 laptops on my network. Two of the desktops are wired, and the last desktop and both laptops are wireless. I am unable to connect to the wireless desktop named "GUESTROOM". When I pull up the router in a browser, it recognizes the computer is there and when I pull up MacAfee on another computer it recognizes that GUESTROOM is part of it's network, but is offline. This started out of the blue yesterday. I have uninstalled/reinstalled the driver for the network adapter and it is not working. Router: Dlink Dir-655 Model: SURFboard SB6121 Connecting via Cox Cable Network Adapter: DLink DWA-131 System: Win XP Home Service Pack 3 I ran the ping and received the following: Windows IP Configuration Host Name . . . . . . . . . . . . : GUESTROOM Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Broadcast IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : NoEthernet adapter Local Area Connection: Media State . . . . . . . . . . . : Media disconnected Description . . . . . . . . . . . : Realtek RTL8139/810x Family Fast Ethernet NIC Physical Address. . . . . . . . . : 00-11-5B-36-17-A6 Ethernet adapter Wireless Network Connection 10: Media State . . . . . . . . . . . : Media disconnected Description . . . . . . . . . . . : D-Link DWA-131 Wireless N Nano USB Adapter Physical Address. . . . . . . . . : 1C-AF-F7-F6-25-50 Ping request could not find host yahoo.com. Please check the name and try again.

What attempts have you made to re-connect to your wireless network, and what were the results of that? It says its disconnected. Have you tried clearing out your wireless networks and re-entering the passphrase to connect?

I started by clearing out the networks and entering the password again Then I went into the router settings and made sure it could see the computer (it could) Then I went into MacAfee Security and made sure it was still trusted on the Home Network (it was, trusted, disconnected) Then I uninstalled and reinstalled the driver I've run CCleaner and rebooted several times, last time I turned the system off instead of rebooting. The computer does find the router, says the signal is strong, password is accepted, but there is no connection A few nights ago I had connection problems on my laptop, but it's running Win 7 and the diagnostic tool was able to correct the problem, whatever it was and connect me again. i have not had any problems with the other laptop. I'm stumped.

I also checked the driver and it says it is installed and working properly.

Well, nevermind. Went back into the room and the CPU was off, couldn't get it turned back on so I rest the power source and when I turned it back on it blew. Computer is totally dead until I get a new power source.