RunDLL32.exe

Run a DLL program. This command is available on all version of Windows from Win95 onwards, but the DLL's and options available do vary considerably. Many options are case sensitive.

Syntax
       RUNDLL32.EXE dll_name,EntryPoint [options]

Examples

 Un-install MS Java Virtual Machine (JVM):
   RUNDLL32 advpack.dll,LaunchINFSection java.inf,UnInstall
   
 Copy a floppy disk
   RUNDLL32 diskcopy,DiskCopyRunDll

 Lock workstation
   RUNDLL32.exe user32.dll, LockWorkStation

 Add a Network Printer

   RUNDLL32 printui.dll,PrintUIEntry /ia /c\\server /m "AGFA-AccuSet v52.3"
      /h "Intel" /v "Windows 2000" /f %windir%\inf\ntprint.inf 

 Add a Local Printer

   RUNDLL32 printui.dll,PrintUIEntry /if /b "Test Printer" /c\\SERVER 
      /f "%windir%\inf\ntprint.inf" /r "lpt1:" /m "AGFA-AccuSet v52.3"

 Add a printer connection that's available to anyone who logs on:

   Rundll32 printui.dll,PrintUIEntry /ga /n\\Server\PrintShare

 Display all the available commands for PRINTUI.DLL

   RUNDLL32 printui.dll,PrintUIEntry /?

   (add/remove print drivers, print queues, preferences, properties etc)

"If you're rich you can buy books. If you're poor, you need a library" - John Kenneth Galbraith

Related commands:

Karl E. Peterson (MVPS) - Most useful rundll32 options
Bruce Sanderson - Setup shared printers (PrintUI.dll)
MVPS.org - Remove or upgrade Java VM
DX21.com - A long list of rundll32 options

CON2PRT - Connect or disconnect a Printer
PRNCNFG - Add, delete, or list printers / connections, set the default printer.
PRNMNGR - Add, delete, or list printers / connections, set the default printer.
REGSVR32 - Register or unregister a DLL
WMIC PRINTER - Set printing options through WMI.
Q189105 - Add Printers with No User Interaction (Win 2000)
Q314486 - Add Printers with No User Interaction (Win XP)