First and foremost, lets clear up some confusion....
There is no such thing as a DHCP card- it's a protocol- not a device.
An easier way to figure out what is going on is go to start>run and type "cmd" without quotes- hit enter. This is going to tell you some information, such as your IP address, subnet, default gateway, if your IP is static or DHCP, etc. Just copy and paste that in your response here. This will help a lot- because it seems to be a bit of confusion.
Also, what utility are you using to try and connect to the wireless network? Reason I ask, is because certain laptops use their own utility, rather than the Windows utility (for good reason), and they tell you what is going on. For instance, try a "ipconfig /release"- it should turn to all zeros. Then type "ipconfig /renew" and see if you get an IP address- the more I think about this, the more it sounds like a winsock issue. Tell me what the message is when you release and renew. If it says that it tried to connect to something that wasn't a socket- winsock issue. This would explain why it says connected, but you can't do anything.