Having a pile of problems at the moment, and none of them I have any idea why they are happening *sigh*

I have a server that is not on my domain and is on a seperate domain, I can access it through remote desktop perfectly fine, but when trying to go into run, and type in the server name/ip adress it wont come up, on any computer on our network, except for the one pc that is on its domain, its a server of a friend and hes leant it to me while he is away so I am doing some stuff with it.

Any Help is much apreciated.

I have disabled windows firewall on it.