I'm not sure if I'm posting this in the right section - apologies if so.
I have 2 Windows XP Service Pack 3 pc's, after being on for a few hours (does not matter if the pc is idle or being USED) the network disappears. When I go to Network Connections from Control Panel its empty. After a restart then all the connections come back and the pc connects to the network again.

I have checked that all the drivers are installed correctly and I have done a virus scan.
I have got no idea what is causing this.

Any ideas\advice???

Thanks so much!Wireless or Wired CONNECTION?
Is this your network or are you riding on someone elses (if wifi)?
If its your connection wifi or wired via Cat5 to computers does the router or modem show a connection loss with the internet or are they showing connectivity handshake LED lit green?Its a wired network.
I think I've solved the PROBLEM. The Workstation service was STOPPING, I set it to manual and started it again and the problem SEEMS to have stopped. It has not dropped its network for 3 days - vs at least twice a day.

Thanks.