You can determine who is using resources on your local computer with the "net" command ("net session"), however, there is no built-in way to determine who is using the resources of a remote computer. In addition, NT comes with no tools to see who is logged onto a computer, either locally or remotely. PsLoggedOn is an applet that displays both the locally logged on users and users logged on via resources for either the local computer, or a remote one. If you specify a user name instead of a computer, PsLoggedOn searches the computers in the network neighborhood and tells you if the user is currently logged on. Full source code is included.
PsLoggedOn's definition of a locally logged on user is one that has their profile loaded into the Registry, so PsLoggedOn determines who is logged on by scanning the keys under the HKEY_USERS key. For each key that has a name that is a user SID (security Identifier), PsLoggedOn looks up the corresponding user name and displays it. To determine who is logged onto a computer via resource shares, PsLoggedOn uses the NetSessionEnum API. Note that PsLoggedOn will show you as logged on via resource share to remote computers that you query because a logon is required for PsLoggedOn to access the Registry of a remote system.
Just copy PsLoggedOn onto your executable path, and type "psloggedon".
PsLoggedOn works on NT 4.0, Win2K, Windows XP and Server 2003.
usage: psloggedon [-?] [-l] [-x] [\\computername | username]
PsLoggedOn is part of a growing kit of Sysinternals command-line tools that aid in the adminstration of local and remote Windows NT/2K systems named PsTools.
Download PsLoggedOn (19KB)
Download PsLoggedOn Plus Source (35KB)
Download PsTools