You cannot get a list of machines on the Browse Network tab when performing a Remote Push Installation to client machines and an error message is displayed.
Microsoft Windows Network raises the error: The list of servers for this workgroup is not currently available, the error code is 6118
This error occurs when the Computer Browser service is not running. This service is disabled by default on newer operating systems.
Enable Computer Browser service:
Note: This service requires File and Printer Sharing to be enabled.
See http://technet.microsoft.com/en-us/library/bb726965.aspx and search for the heading "Computer Browser Service" for more information on this service and its defaults in Windows 2008.
Use the "Search Network" tab to locate machines and install to them. This option does not depend on the Computer Browser Service.