Help with laptop/desktop setup

Well i got my g/f a laptop for graduation and i didn't want to spend money on a router and have to set all that up. My desktop mobo has 2 ethernet ports, one connected to the cable modem. and the other one i plugged into the laptop.

Both computers have XP and I used the network setup wizard on both computers, used my cable service activator provided by my cable company and it connected to the net and i updated the laptop and it worked fine on thursday. I tried it again sunday and I CANNOT get it to connect to the internet or even to access shared folders on the desktop.

I plug in the cable and on both computers it says connected, and when i unplug it, both say disconnected. I've reset the cable modem resetup the network using the wizard many times and it will not work. I've done system restore on both computers back to thursday night with no luck. I dont think i made any serious changes to either computer. I figured when we got back sunday night it would plug right in and go. =(

please please please suggestions before i have to call tech support?

 

The PC is it on all the time if so you may want to setup internet connection sharing on the Ethernet port been used for the lan this will set that IP to 192.168.0.1 all you should have to do is leave the laptop to detect IP and it should connect you may want to assign it an ip if you do try 192.168.0.10 of course subnet of 255.255.255.0, gateway 192.168.0.1 and primary dns of 192.168.0.1. and see if that helps.

 

zone alarm on the desktop. just the windows firewall on the laptop.