We have three computers between which we have a LAN. We are connected through a switch. The trouble I am having is with my new laptop which is running windows vista home premium.

I am having trouble with connecting to my office LAN. I cannot turn on the file sharing under network & sharing. In system properties > computer name > to rename this computer, click change. When I click on change the WORKGROUP is grayed out although I can make changes to the Computer name. I think its there where the problem lies.

When I try to turn on file sharing nothing happens and it still remains off. And when I try to turn on file and printer sharing I get an error message saying RPC server is not available. When I looked in the services I saw the RPC is started and running.

Can anyone help me out here.

I forgot to add one more thing. I am connected to internet via our office server running win xp) which has broadband internet connection. So when I try to ping to our office server it sucessfully does but when I try to ping to my laptop from our office server I couldnt ping..

Why? Is there no one who can answer this query ...