WEP secured connection detected as unsecured, and won't connect anyway

My housemate spent yesterday jerking around with everyone elses computers, and afterwards they couldn't connect to our WPA secured wifi. So he changed it to WEP and they could. But now I can't connect to the WEP secured connection

My computer detects the network as an unsecured connection, when I try to connect it the 'trying to connect' message comes and then goes without any messages about it failing to connect.

It's a Netgear Modem, and my wifi adapter is an Intel pro/wireless 2400BG. I updated the drivers for it through a wired connection last night so it should all beup to date. I'm on a HP Tc4200 with Windows XP Tablet edition.