What I suggest (this is what I do when reinstalling my software) is to not use the Wizards that come with Windows. Make sure the drivers are copied from your CD for the wireless adapter. Unplug the adapter and then plug it back in so that windows detects new hardware. Then, as the software to run the connection isn't installed, download a program called WinC from Cirond (30-day trial, but I'll talk to you on MSN about that).
As for the DHCP server, I recommend turning this off once you can actually connect and setting the IP, Default Gateway, Subnet Mask and DNS server addresses youself. This not only gives a static IP, but (with my PC at least) connects faster as the router doesn't have to assign an IP address for you.
If nothing works to get the laptop to find the connection, try installing the Wireless Network to another PC to see if that installs OK and detects the network.
PS: Even though theres probably a low risk, I wouldn't have posted your WEP key online
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