You can lock the Windows 2000 or XP desktop with a click of an icon. Create a shortcut icon on the desktop to run the following command:

rundll32.exe user32.dll,LockWorkStation

Rundll32.exe is an application included with Windows that executes functions in dynamic link libraries (DLLs). Most applications (and Windows) use DLLs to share code between multiple applications or multiple modules within a single application. There are lots of other tasks you can accomplish with Rundll32.exe. You can execute these commands from a console or incorporate them into scripts or batch files to help you quickly access certain features in the user interface for configuring the operating system or hardware.

• The following command starts the Add Printer Wizard:
  Rundll32.exe printui.dll,PrintUIEntry /il
  
• If you want to add a standard TCP/IP port for printing, use this command:
  Rundll32.exe tcpmonui.dll,LocalAddPortUI
  
• You can easily create new shared folders through the New Share dialog box. Use this command to open it:
  Rundll32.exe ntlanui.dll,ShareCreate
  
• Another function you can access through Ntlanui.dll is the Shared Directories dialog box. Here's how to open it:
  Rundll32.exe ntlanui.dll,ShareManage
  

Related tips:

• Create Lock Desktop Icon
  
• Launch URL from Desktop Icon
  
• WinKey Shortcuts
  

I have seen tips using similar syntax to create a shutdown shortcut icon:

rundll32.exe user32.dll,ExitWindowsEx Actually that tip works for Windows NT but not Windows 2000 or Windows XP. You can use the Resource Kit shutdown.exe for Windows NT, Windows 2000, or Windows XP. See Shutdown Windows NT or Win9x at specific time each day for an example use of Shutdown.exe.

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