I'm writing a utility to scan lots of systems. Before I try to read their registry and disk drives I need to know whether they are 'on' or 'off'. I've used the www.allapi.net
API routines to send a PING, but it still takes 4 - 6 seconds to return if the PC is off, and with a lot of machines that can soak up a lot of time.
In the NT4 Server Manager program, it displays a list of servers and workstations very quickly, with 'unavailable' systems greyed out. How does it do this? Is there an API that returns a system's online status?