Yes, if you turn DHCP back on, it will work.

Just kidding. Here are the steps:
Start
Run
NCPA.CPL
OK
It should show you a list of icons representing the network cards in the system. Locate the wireless one, select it, right-click and select PROPERTIES.
Look for either "TCP/IP properties" or "Internet Protocol Version 4" properties, depending on which OS you're running. Select it and press the PROPERTIES button below it.
Select "OBTAIN AN IP ADDRESS AUTOMATICALLY" and "OBTAIN DNS SERVER AUTOMATICALLY" and confirm, confirm, confirm.
"Automatic IP Address" is what "DHCP" means, you see.