I got this problem once. You can try to remove the card, and remove the driver and then reinstall, but simply removing the driver and reinstalling it should fix the problem. Open control panel, open system, click the hardware tab, then click on device manager. Look under network adapters and remove all drivers that relate to the wireless card. Restart the computer. IF after Windows boots and it does not detect the wireless card go back to the contol panel and double-click on "Add New Hardware" and put the installation CD in the CD drive. Hopefully it will reinstall and the problem will be fixed. If the problem still presists, then either your router and/or wireless has gone bad and needs to be replaced. Hope this helps you out.
A) On my home network, I lose my wireless connection and need to reconnect every 15 minutes or so.
B) The real weirdness (to me) is that XP always shows me as "not connected" to my home network, even when I'm online. Like right now.`
C) Sometimes I can't "reconnect" with a button click. When this happens, I look under Wireless Connection Properties > Wireless Networks, and find that my WEP key has been removed and the checkbox is selected next to "The key is provided for me automatically"--all this without my having changed the settings.
I'm running Windows XP SP2 on a Dell Inspiron B130, connecting to a Linksys WRT54G v. 5 router, chained from an Actiontec DSL gateway.
My roommate connects to the same network with his laptop. For a while his browser wouldn't connect to eBay or MySpace, but his laptop has been connecting perfectly fine since we restarted the wireless equipment recently. My woes were the same before and after, so I think the problem is with my settings.