rundll32.exe is a process which executes DLL’s and places their libraries into the memory, so they can be used more efficiently by applications. This program is important for the stable and secure running of your computer and should not be terminated. Nowadays many virus, Trojans, worms use this to affect the computers. But if you study this process it can be very useful. So I’m starting some tips and tricks on this in coming blog posts.

The syntax for using Rundll32.exe is as follows:

RUNDLL32.EXE <dllname>,<entrypoint> <optional arguments>

The DLL name should not contain any spaces, commas or quotation marks. If the DLL name does contain spaces, use the short (8.3) version of the file name. This is the name which you’ll see if you use that file in DOS environment. Note the comma between the DLL name and the entry point. Also, the name of the entry point function is case-sensitive and there should not be any spaces between the DLL name, the comma, and the entry point function name. Full path of DLL should be given unless it exists in system folders.
There are a number of commands employing Rundll32.exe that can be entered into Start -> Run, a command window, or used in scripts. A common use is to open various Control Panel applets. (Another method specific to Control Panel is discussed here.) For example, to open the Control Panel applet for configuring the display settings enter

rundll32.exe shell32.dll,Control_RunDLL desk.cpl,,3

Different tabs for the Desktop applet can be opened by changing the number at the end that is part of the argument. All of the Control Panel applets and their tabs can be opened this way by using the relevant CPL file and the appropriate tab number as arguments. The operating system also uses this method to display Control Panel. In fact, Control Panel applications are the most commonly mentioned examples in discussions of using Rundll32.exe.

To be Continued…