The fact that services can exist without desktops is the advantage that makes services desirable. The various situations during which a process is installed as a service are:
· When a process is needed that starts when the computer starts and stops only when computer stops
· Hardware drivers, or applications controlling or monitoring hardware attached to a system; e.g. monitoring for plug and play devices
· A process is required that operates even when no users are logged on to the computer; e.g. Anti Virus programs, Disk Monitoring programs etc.
· Parts of Operating System itself; e.g. RPC (Remote Procedure Call) server, DCOM (Distributed Component Object Model) server, etc.
· Software which handles communication from users on other machines, who have logged on to this machine; e.g. FTP Server, Web Server etc.