Batch file world

RUNDLL and RUNDLL32
RUNDLL and RUNDLL32 are two utilities supplied with Windows 95 and later.They can call DLL functions from the command line, allowing us to create extremely powerfull batch files.
Some examples:
Start Control Panel applets (2)
Open Install new modem wizard
Start "Add New Hardware" wizard
Open the "Unplug or Eject Hardware" wizard (Windows 95)
Open Device manager
Install a screensaver
Lock the screen (Windows 2000)
Redraw the screen (Windows 95)
Rearrange the windows on the screen (Windows 95)
Change screen resolution (Windows 9x with PowerToys' QuickRes installed)
Disable mouse and/or keyboard (Windows 9*/ME)
Halt system
Start "Add New Printer" wizard
Open "Connect to Printer" dialog
Open the Printers folder
Print a test page (Windows 95 and later)
Manage printer settings (Windows 2000)
Add a TCP/IP printer port
Clear Internet Explorer branding (the annoying company name in IE's title bar)
Open the dialog box for editing the Favorites in Internet Explorer
Delete Internet Explorer 7's browsing history, cookies and temporary files
Start GUI mode disk format
Start GUI mode diskcopy
"Map Network Drive" dialog (Windows 95)
Manage shares
Create a new share
Open the Network ID wizard
Open the Add network place wizard
Logoff Windows (1)
Reboot (1)
Shutdown (1)
Activate suspend mode (1) (Windows 2000 and later)
Show "System setting changed, do you want to reboot now?" dialog (Windows 9*)
Display NT's "About" dialog
Open a file with Windows' "Open as" dialog
Open a .ZIP file in Explorer (Windows XP)
Swap your mouse to left handed use
Start "DialUp Connection" wizard (Windows 95)
Start DialUp Network
Open the Fonts folder
Open an Active Directory Search dialog (Windows 2000 and later)
Activate registry changes in HKEY_CURRENT_USER without logging off (Windows 2000 and later)
Remove Messenger (Windows XP)
Repair IE 6 (Windows XP)

Start Control Panel applets (2)
General syntax:
RUNDLL32 SHELL32.DLL,Control_RunDLL filename.CPL,@n,t
where:
filename.CPL
is the name of one of Control Panel's *.CPL files,
n
is the zero based number of the applet within the *.CPL file, and
t
is the number of the tab for multi paged applets
Examples:
Date/time applet, Time Zone tab:
RUNDLL32 SHELL32.DLL,Control_RunDLL TIMEDATE.CPL,@0,1
Desktop applet, Screensaver tab:
RUNDLL32 SHELL32.DLL,Control_RunDLL DESK.CPL,@0,1
Network applet, Protocols tab:
RUNDLL32 SHELL32.DLL,Control_RunDLL NCPA.CPL,@0,2
Network applet, Adapters tab:
RUNDLL32 SHELL32.DLL,Control_RunDLL NCPA.CPL,@0,3
System applet, Environment tab:
RUNDLL32 SHELL32.DLL,Control_RunDLL SYSDM.CPL,@0,2
An alternative approach is using CONTROL.EXE.However, if you want to make your batch file wait for the Control Panel applet to be closed, you'll have to use the RUNDLL32 command with START /WAIT
General syntax:
CONTROL.EXE filename.CPL,@n,t
where:
filename.CPL
is the name of one of Control Panel's *.CPL files,
n
is the zero based number of the applet within the *.CPL file, and
t
is the number of the tab for multi paged applets
Examples:
Date/time applet, Time Zone tab:
CONTROL.EXE TIMEDATE.CPL,@0,1
Desktop applet, Screensaver tab:
CONTROL.EXE DESK.CPL,@0,1
or alternatively, in Windows 2000 & XP:
CONTROL.EXE DESK.CPL ,@ScreenSaver
Note the space between the *.CPL file name and the comma.This seems to work for DESK.CPL only.Use the description on the tab, remove any spaces.Credits: Neil J. Rubenking, in one of his articles in PC Magazine.Tip: Leslie Katz

Back to the top of this page . . .
Open Install new modem wizard
RUNDLL32 modemui.dll,InvokeControlPanel
Credits: Jeffrey W. Horning (posted on JSI FAQ)

Back to the top of this page . . .
Start "Add New Hardware" Wizard
(Windows 95)
RUNDLL SYSDM.CPL,InstallDevice_Rundll
Credits: Faris Mlaeb

Back to the top of this page . . .
Open the "Unplug or Eject Hardware" wizard
(Windows 2000 or later, or Windows 98 SE with hotplug.dll installed):
RUNDLL32 SHELL32.DLL,Control_RunDLL hotplug.dll
Credits: Chris S./Dx21.com

Back to the top of this page . . .
Open Device manager
RUNDLL32 devmgr.dll DeviceManager_Execute
Credits: Jeffrey W. Horning (posted on JSI FAQ)

Back to the top of this page . . .
Install a screensaver
(copy the *.SCR file to the Windows directory first) (2):
RUNDLL32 DESK.CPL,InstallScreenSaver C:\WINNT\SYSTEM32\Default.scr
(To invoke the screensaver use:
C:\WINNT\SYSTEM32\Default.scr /S
Tip by "UnhappyEggWhisk" on forums.somethingawful.com)
The directory shown is for Windows NT 4/2000, modify for Windows 9x/XP

Back to the top of this page . . .
Lock the screen
(Windows 2000)
RUNDLL32 USER32.DLL,LockWorkStation
Credits: Steven Clements (posted on alt.msdos.batch.nt)

Back to the top of this page . . .
Redraw the screen
(Windows 95)
RUNDLL USER,repaintscreen
Credits: Faris Mlaeb

Back to the top of this page . . .
Rearrange the windows on the screen
(Windows 95)
Cascade:
RUNDLL32 USER,cascadechildwindows
Tile:
RUNDLL32 USER,tilechildwindows
Credits: Faris Mlaeb

Back to the top of this page . . .
Change screen resolution
(Windows 9x with PowerToys' QuickRes installed):
RUNDLL DESKCP16.DLL,QUICKRES_RUNDLLENTRY hresxvresxbpp
Where hres is the horizontal resolution in pixels, vres is the vertical resolution in pixels, and bpp is the number of bits per pixel.The following example will set the screen resolution to 800 x 600 at 256 colors (28 colors = 8 bits per pixel)
RUNDLL DESKCP16.DLL,QUICKRES_RUNDLLENTRY 800x600x8
Credits: William Allen (posted on alt.msdos.batch)

Back to the top of this page . . .
Disable mouse and/or keyboard
(Windows 9*/ME)
RUNDLL KEYBOARD,DISABLERUNDLL MOUSE,DISABLE
There is an ENABLE function too, but I haven't found the right syntax yet. Without any further parameters it only halts the system without warning (Windows 95). You will probably need the other RUNDLL commands to do a "clean" reboot.
Credits: Koro das Master

Back to the top of this page . . .
Halt system
RUNDLL MOUSE,ENABLE
Credits: Faris Mlaeb

Back to the top of this page . . .
Start "Add New Printer" wizard
RUNDLL32 SHELL32.DLL,SHHelpShortcuts_RunDLL AddPrinter

Back to the top of this page . . .
Open "Connect to Printer" dialog
RUNDLL32 WINSPOOL.DRV,ConnectToPrinterDlg
This commands opens the "Connect to Printer" dialog, as you might have guessed. I don't see any useful application yet, but maybe you do.

Back to the top of this page . . .
Open the Printers folder
RUNDLL32 SHELL32.DLL,Control_RunDLL MAIN.CPL @2
or for Windows 2000:
RUNDLL32 SHELL32.DLL,SHHelpShortcuts_RunDLL PrintersFolder
Credits: Pascal Rebsamen
Note:
To create a shortcut in the Start Menu to open the Printers folder, create a directory using one of the following commands.
Windows 9x (without roaming profiles):
MD "%windir%\Start Menu\Programs\Printers.{2227A280-3AEA-1069-A2DE-08002B30309D}"
Windows NT 4/2000:
MD "%USERPROFILE%\Start Menu\Programs\Printers.{2227A280-3AEA-1069-A2DE-08002B30309D}"

Back to the top of this page . . .
Print a test page
(Windows 95 and later; unfortunately this command does not always work):
RUNDLL32.EXE SHELL32.DLL,SHHelpShortcuts_RunDLL PrintTestPage
Or for Windows 9x (source: Daniel U. Thibault):
RUNDLL32.EXE MSPrint2.DLL,RUNDLL_PrintTestPage

Back to the top of this page . . .
Manage printer settings
(Windows 2000)
RUNDLL32 PRINTUI.DLL,PrintUIEntry /?
This will display an extensive list of available functions and many examples.View this same list in HTML.

Back to the top of this page . . .
Add a TCP/IP printer port
RUNDLL32 tcpmonui.dll,LocalAddPortUI
Credits: Jeffrey W. Horning (posted on JSI FAQ)

Back to the top of this page . . .
Clear Internet Explorer branding
(the annoying company name in IE's title bar)
RUNDLL32.EXE iedkcs32.dll,Clear
Credits: "pradeep" (posted on Go4Expert Forum)

Back to the top of this page . . .
Open the dialog box for editing the Favorites in Internet Explorer
RUNDLL32.EXE shdocvw.dll,DoOrganizeFavDlg
Credits: "pradeep" (posted on Go4Expert Forum)

Back to the top of this page . . .
Delete Internet Explorer 7's browsing history, cookies and temporary files
RUNDLL32.EXE inetcpl.cpl,ClearMyTracksByProcess n
Where n can have the following values:
1
delete browsing history (list of visited sites)
2
delete all cookies
8
delete temporary files (cache)
16
delete all saved forms data
32
delete all saved passwords
255
delete all of the above
4351
delete all of the above and all settings stored by add-ons
The use of powers of 2 suggests that one can combine (add) these values, e.g. 40 to delete temporary files (8) and passwords (32) simultaneously, but I didn't test this assumption yet.
Credits: Herby on neowin.net

Back to the top of this page . . .
Start GUI mode disk format
RUNDLL32 SHELL32.DLL,SHFormatDrive
Back to the top of this page . . .
Start GUI mode diskcopy
RUNDLL32 DISKCOPY.DLL,DiskCopyRunDll
Credits: Media Chance

Back to the top of this page . . .
"Map Network Drive" dialog
(Windows 95)
RUNDLL32 USER,wnetconnectdialog
and for Windows XP:
RUNDLL32 SHELL32.DLL,SHHelpShortcuts_RunDLL Connect
Credits: Faris Mlaeb (Windows 95) and Ian Freeman (Windows XP)

Back to the top of this page . . .
Manage shares
RUNDLL32 ntlanui.dll,ShareManage - Shares
Credits: Jeffrey W. Horning (posted on JSI FAQ)

Back to the top of this page . . .
Create a new share
RUNDLL32 ntlanui.dll,ShareCreate
Credits: Jeffrey W. Horning (posted on JSI FAQ)

Back to the top of this page . . .
Open the Network ID wizard
RUNDLL32 netplwiz.dll,NetAccWizRunDll
Credits: Jeffrey W. Horning (posted on JSI FAQ)

Back to the top of this page . . .
Open the Add network place wizard
RUNDLL32 netplwiz.dll,AddNetPlaceRunDll
Credits: Jeffrey W. Horning (posted on JSI FAQ)

Back to the top of this page . . .
Logoff Windows (1)
Logoff Windows 98:
RUNDLL SHELL32.DLL,SHExitWindowsEx
Logoff Windows 98 and run Explorer after relogon:
RUNDLL SHELL32.DLL,SHExitWindowsEx 4
Logoff Windows NT 4:
RUNDLL32 USER32.DLL,ExitWindowsExRUNDLL32 USER32.DLL,ExitWindowsEx
This is not a mistake, the command usualy must be called twice before anything happens.

Back to the top of this page . . .
Reboot (1)
Windows 95 (not reliable, sometimes only shutdown):
RUNDLL USER.EXE,ExitWindowsExec
Windows 98:
RUNDLL SHELL32.DLL,SHExitWindowsEx 2
Windows NT 4:
@ECHO OFFPUSHD "%temp%"ECHO [Version] > {out}.infECHO signature=$chicago$ >> {out}.infECHO [defaultinstall] >> {out}.infRUNDLL32 SETUPAPI,InstallHinfSection DefaultInstall 1 {out}.infDEL {out}.infPOPD
(original batch file by Walter Zackery, adapted for readability)

Back to the top of this page . . .
Shutdown (1)
Windows 95:
RUNDLL USER.EXE,ExitWindows
Windows 98:
RUNDLL SHELL32.DLL,SHExitWindowsEx 1
or:
RUNDLL32 KRNL386.EXE,exitkernel
(will also power down ATX boards)

Back to the top of this page . . .
Activate suspend mode (1)
(Windows 2000/XP)
RUNDLL32 PowrProf.dll, SetSuspendState
Credits: TechRepublic's Windows XP Newsletter & Graham Smith.

Back to the top of this page . . .
Show "System setting changed, do you want to reboot now?" dialog (1):
(Windows 9*)
RUNDLL SHELL.DLL,RestartDialog

Back to the top of this page . . .
Display NT's "About" dialog
Showing version, servicepack, registered owner and amount of physical memory:
RUNDLL32 SHELL32.DLL,ShellAboutW

Back to the top of this page . . .
Open a file with Windows' "Open as" dialog
RUNDLL32 SHELL32.DLL,OpenAs_RunDLL filename

Back to the top of this page . . .
Open a .ZIP file in Explorer
(Windows XP)
RUNDLL32.EXE ZIPFLDR.DLL,RouteTheCall zipfile.ZIP
Unfortunately, there seems to be no (native) command to copy files into the .ZIP file

Back to the top of this page . . .
Swap your mouse to left handed use
(tip from "Speedy Gonzales")
Windows 95:
RUNDLL USER.EXE,SwapMouseButton
Windows NT:
RUNDLL32 USER32.DLL,SwapMouseButton
I know of no command yet to undo this, but the following will get you close:
CONTROL MAIN.CPL
or:
RUNDLL32 SHELL32.DLL,Control_RunDLL MAIN.CPL,@0,1

Back to the top of this page . . .
Start "DialUp Connection" Wizard
(Windows 95)
RUNDLL RNAUI.DLL,RnaWizard
Credits: Faris Mlaeb

Back to the top of this page . . .
Start DialUp Network
START RUNDLL32 RNAUI.DLL,RnaDial exact name of dialer entryTRACERT -h 1 -w 1
The RUNDLL command starts DUN, the TRACERT command is supposed to actually start the dialing process, assuming automatic dialing is enabled.Since I do not have access to any PC with DUN installed, I could not test the TRACERT command's effect.
Credits for these commands: Michael J. Gregg and Tom Lavedas
Use the RASPHONE command in Windows NT, which can also hang up the connection
Credits: Simon Sheppard.

Back to the top of this page . . .
Open the Fonts folder
RUNDLL32 SHELL32.DLL,SHHelpShortcuts_RunDLL FontsFolder
Credits: Media Chance

Back to the top of this page . . .
Open an Active Directory Search window:
RUNDLL32 dsquery,OpenQueryWindow
This allows you to search Active Directory for users or computers, though only a limited part of the properties is accessible.
Credits: TechRepublic's Windows XP e-Newsletter for August 5, 2004

Back to the top of this page . . .
Activate registry changes
in HKEY_CURRENT_USER without logging off (Windows 2000 and later):
RUNDLL32.EXE USER32.DLL,UpdatePerUserSystemParameters ,1 ,True
Credits: Pete Smith.

Back to the top of this page . . .
Remove Messenger
(Windows XP)
RUNDLL32 advpack.dll,LaunchINFSection %windir%\INF\msmsgs.inf,BLC.Remove
Credits: Pascal Rebsamen (posted on WinBoard)

Back to the top of this page . . .
Repair IE 6
(Windows XP)
RUNDLL32 setupapi,InstallHinfSection DefaultInstall 132 %windir%infie.inf
Credits: Pascal Rebsamen (posted on WinBoard)

Back to the top of this page . . .

Notes:
(1)
See my Shutdown page for more information and examples on reboot and shutdown command lines.

(2)
By associating *.CPL files with the commandRUNDLL32 SHELL32.DLL,Control_RunDLL %1,@0and *.SCR files withRUNDLL32 DESK.CPL,InstallScreenSaver %1you can open and/or install them by doubleclicking on their icons.

Back to the top of this page . . .

Examples
Install a screensaver
The following batch file installs a screensaver if one is specified, and opens the Control Panel applet at the right tab to enable adjustment of its settings (tested in NT only):@ECHO OFF
IF "%1"=="" GOTO Interactive
IF NOT EXIST %SystemRoot%.\System32\%~nx1 GOTO Interactive
RUNDLL32 DESK.CPL,InstallScreenSaver %~f1
GOTO End
:Interactive
RUNDLL32 SHELL32.DLL,Control_RunDLL DESK.CPL,@0,1
:End




I am interested to hear about other possible uses for RUNDLL32.Please send me your tips or comments by e-mail: info@robvanderwoude.com

Back to the top of this page . . .

More to explore

An extensive list of RUNDLL commands with good search capabilities can be found at Dx21's RunDLL32 section.
For programmers, there is more information on Microsoft's Windows 95 Rundll and Rundll32 Interface page.
Peter A. Bromberg's Short RunDll32 Primer for Developers.
At The Visual Basic Developers Resource Centre a list of Control Panel Functions for Windows 9x/NT through RUNDLL can be found (a tip from my former collegue Adriaan Westra; thanks).
An extensive list of Control Panel related and other RUNDLL commands can be found at Media Chance's RUNDLL FAQ page.
Jeffrey W. Horning provided a list of Undocuments paths to Windows 2000 tools (thanks for Viju Chellamuthu, who mailed me the link).
Search Microsoft.com for more info on INF files.