Thanks to everyone who suggested things I should try to get my daughter's PC to connect to my home wireless network. But no success. :-(
I have a Belkin wireless router/modem, serving three PCs - two desktops and a laptop. They're all running Windows XP (one vanilla, one SP1 and one SP2). Everything was fine until I had to re-install my daughter's desktop PC.
Ever since I have been unable to connect to the home network. I primarily want to connect to the Internet - not share resources.
I know that it's not a hardware problem since (a) I've tried two desktop wireless network cards (both Belkin) and (b) Control Panel reports that the cards are working OK.
I installed and re-installed the Belkin software several times. I always remove the card (as recommended) before re-installing the software. It makes no difference.
I can see the home network on my daughter's PC. When I double-click the Belkin icon in the system tray (which is always red when it should be green), I can see the home network in the list of "Available networks" and "Preferred networks". I just can't connect.
I've disabled all security (it was never enabled) on the router and all of the cards (in each of the PCs).
I've tried using Windows to manage the cards and also the Belkin software. It makes no difference.
One odd thing. When I select the "Link status" tab, I get nothing - no network, no packets, no signal, no noise - nothing. But when I select "Site monitor" I see a good (green) signal and a good signal/noise ratio. Weird. More confirmation that the card is transmitting and receiving OK.
I'm really puzzled by this and about to reformat her machine in desperation.