Wireless Setup On Gateway GT4016

My Laptop (Dell D600) appears to recognize the wireless link but my Desktop Gateway GT4016 does not show any sort of wireless network when I invoke the "set up Manually" feature. I've read somewhere that a Network Manager exists somewhere in Ubuntu 8.04 but I can find nothing of the sort. Admittedly I have practically zero knowledge of Ubuntu although I have spent hours and hours and hours attempting to get Ubuntu and Windows XP to work with each other and have finally succeeded (I think).

I have an internet connection on both the desktop and the Laptop. I have loaded the Netgear 802.11 software into the laptop to allow the Wireless Adapter to operate. What must I do to connect the two machines together wirelessly?