please help

[Nisha26]

I had set up internet sharing between the 2 computers and everything was working fine for about a month and then suddenly one day, out of the blue, the network goes down (ie. it would appear that neither computer is connected to each other... though the main computer is still accessing the internet just fine.). I've checked all the cables, replaced the network cards, reinstalled XP on both machines, but am still unable to network the 2 computers together again. the hub activity lights are blinking everytime I try one both connections and all lights are green but I am unable to ping either computer from the other so obviously, somewhere, there is a breakdown in the connection. I have tried to repair the connection on the old computer and it comes up with the error message "unable to renew IP address" mostly and occasionally adds "unable to flush the ARP cache", so I suspect the problem lies with the secondary machine. These errors occur on both ethernet cards that I have put in that machine whenever I try to repair either connection (only one is is use at a time, the other, I have disabled). Any ideas as to how to fix this??? :confused: :confused: :confused:
:confused:

[Davey]

You've not got a firewall between the two machines have you?

[Nisha26]

i dont have any kind of a firewall. i mean i didnt specify for one recently. it was workign fine till few days back. could you please tell me how to remove if i already have one.