Firstly I'd like to say thanks for the replies!
@Flame: I didnt just 'find' it in the the street lol... no no no, it was one of my dad's old ones, but he doesnt need it anymore... So I have commendeered it.
As for the different OS's well I dont really want to format my 2000 machine (let alone not having an XP cd) as it has alot of stuff on it, and i only just formatted recently... I also want to keep the XP OS on the other machine, as its usful for playing some of my older games!
@Robertmiller: I have set all the workgroups in the house to HOME. Also the ip addresses being used between the two computers in my room is '172.168.12.X' but i dont know what you mean by the routers IP? Also the subnet mask is '255.255.0.0'.
@Neil: I do have a firewall on both machines but I have them disabled while I tried pinging does nothing it seems :S
Also it seems the networking wizard doesn't work on a 2000 machine (go figure), so that kinda buggered up.
And good idea I'll quickly try switching routers