To avoid confusion when upgrading or doing an install.  We have had instances, if the old server is still on line, where a client install on a brand new computer was done from the old server instead of from the new server.

1. either shut down 1st server or unplug from network or turn off BW "sage" services on server

2. Are you trying to have access to both servers with BW on the same network? I 've not tried this

3. You will be uninstalling BW at the clients PCs & reinstalling to access the new server

4. Make sure to use the new server name  \\OLD_SERVER     \\NEW_SERVER while installing

and all client installs point correctly to "new" during their setups

as Yoda would have said "there is is no WHY there is only DO"