Problems playing games over network

[TWiTCH]

im currently trying to play some games over my network (computer to computer connection) but they dont see each other!
im running windows XP Pro, with TCP/IP, client for Microsoft network, QoS Packet Schedualer and file and printer sharing.
am i missing something or do i have to set them up, i have just recently reformated them so they are automatically set up, but they are running of the same windows XP serial key, can that be a problem??:confused:

[Jimi_l]

Make sure both games are running the same version (both updated with the same patches or upgrades).

Barring that you will need to run through the network basics:

Make sure the XP firewall is off as well as any other firewall (Zonealarm for example).

Make sure the machines can ping each other. If they can't chances are you network protocols are not set up correctly.

Run the Windows networking wizard on one machine, make a network floppy when asked, and run it on the other machine

If this is a NIC to NIC connection, you need a crossover cable instead of a straight cable. Hold the two cable ends side by side and compare them to this description-

http://hankfiles.pcvsconsole.com/answer.php?file=327

Good luck,

Jimi_l