I have 3 windows xp machines and the first two are desktops and they play games together all the time without a problem. Now the third computer a laptop (not sure that it matters) i hook into the network but neither computer sees its games. I have tried disabling the firewall and making sure it was connected to the right network but i am still having the same problems. 

Any help in solving this would be greatly appreciated. BTW i am not very good at this networking thing.

Is it on the same workgroup?

What do you mean?

Yes, i changed them all but the third computer still isn't being seen by the other two.

Maybe try sharing settings.

Are they connected with cables or wireless?

Wired. 

Maybe check IP addresses and subnet masks

Try resetting your router. That might do the trick.

Do you also have a wireless network running?  Make sure the Laptop isn't connecting to the WIreless one or a different wireless one. 

How is your network setup? 

(IE: Modem -> Router -> 3 PCs)? 

Check the security settings on the third one. Allow sharing. 

Reboot your PC after you make changes.

Make sure they are in the same workgroup (MSHOME, or etc)

Do you assign IP addresses manually or via DHCP? Can You ping Your desktops from the laptop, i.e. what do you get when you run this on your laptop?

ping <desktop's ip address>

The workgroup should not really matter.