Got my laptop, now what?

My "new" laptop/tablet arrived today! I don't have a wireless router, but I do have onboard wireless on my motherboard. I have the P5K-something or other, and its supposed to support 802.11b/g. The laptop is the Acer C100, which supports 802.11b. What I want to do is set it up so that my main PC allows the laptop to surf the net/transfer files. I believe I need to enable ICS on the main PC, not sure what I need to do to the laptop. Any links/tips would be great. (laptop is running XP tablet edition w/SP3, the desktop is running XP student edition/XP pro. Its only up to SP2, but its mostly updated.)

Edit: From what I've read online, I'm supposed to set up an "ad hoc" network. Instructions are here.

http://www.microsoft.com/windowsxp [...] ril08.mspx

My problem is my "host" computer (desktop) doesn't show the "wireless networks" tab. Any idea on why this is?

Edit 2: Went to Asus's website and downloaded the software needed. I had the drivers installed, but there was special Asus software that you use to configure the wifi. Now that its on my computer I have the tab, and the laptop and desktop can see each other. (or at least the desktop can see the laptop. I did have to give it an IP address.) I'm trying to enable ICS now, but only the wired NICs are showing. The wireless isn't in the list. Any clues?