Windows XP in a Nutshell

Name

Rundll32 — \windows\system32\rundll32.exe

Synopsis

Run a single routine in a DLL file from the command line.

To Open

Command Prompt → rundll32

Usage

rundll32 filename,function_name [function_arguments . . . ]

Description

Rundll32 provides “string invocation,” which lets you execute a command buried in a Dynamic Link Library (DLL) file.

Rundll32 accepts the following options:

filename

The filename of a DLL (.dll) file.

function_name

The case-sensitive name of a function in the DLL file.

function_arguments

Any parameters used by function_name; refer to the function’s documentation for details. Note that any string parameters are case sensitive.

Examples

The following example starts the “Network Setup Wizard” (note that no parameters are required for this one):

rundll32.exe hnetwiz.dll,HomeNetWizardRunDll

This batch file allows you to display an “Open As” dialog box for unknown file type .xyz without actually having a file of type .xyz handy (see Appendix C for more information on batch files):

echo blah blah blah > foobar.%1
rundll32 shell32.dll,OpenAs_RunDLL foobar.%1

Then type the following at a command line:

C:\>openas xyz

Notes

Rundll32 provides dynamic linking to functions exported from 32-bit Dynamic Link Libraries. Rundll, the 16-bit equivalent found in earlier versions of Windows, is not included in Windows XP.