Are your machines setup in a Workgroup topology or a Domain topology?
It makes a difference. You may try creating the same User Account on all machines in all networked computers. If you are using a Workgroup topology, each User Account should use the username and password combination to login on each machine. Also, you will want to make sure that each User Account is a member of the same Local Goup on each machine.
Chances are with only three systems on your network you are probably using a Workgroup toplogy. As such, you will need to put the same User Accounts, with the same access, on each and every machine in your network.
Workgroups do not utilize a central Domain Controller to authenticate each User Account on each machine on the network. Therefore, in a Workgroup topology, if you don't setup the same User Accounts, with the same user credentials (username/password) on each machine, you may have a conflict in access to other machines on your network.
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Edited by Cyb3r_Ninj@, 14 May 2008 - 09:49 PM.