Win Xp Connecting to Mac Osx


I just built a new computer that is using Windows XP, and i'm trying to connect it to the mac's built-in-ethernet. I've gone in the settings of the Mac, enabled everything that I would need to enable in the Sharing perferences, and i'm "Sharing my Airport connection". The problem is that, I cannot connect in Windows XP to the internet, or even in the Mac's "". The overview:

The Mac is the main source of the internet, through Airport...

The PC (winxp) is trying to connect to the internet, through the Mac's built-in-ethernet...

I have enabled (or so I believe) everything i'm suppose to in the Mac's perferences. Any suggestions?