I am having a really hard time. I have two computers:

ASUS 900: Running Windows XP
Dell Studio 15: Running Windows Vista

I am trying to install World Of Warcraft by sharing the disc through an ad-hoc network. I have both computers connected but am completely unsure where to go from here. I have spent nearly 3 hours messing with it, and of course it would be easier to go buy a external CD drive but at this point I am more aggervated that I cannot achieve what I am trying to do. So where do I go from here?

I believe the computers are connected, I have the disc in the Dell.

How to configure file sharing in Windows XP (http://support.microsoft.com/default.aspx?kbid=304040)

Read the above article on file sharing and see if this helps you.
Ad-Hoc connetions have a reputation of being difficult sometimes to share files over. Might just think about buying a 4port network hub from BestBuy. You can get a cheap one for like $20.