Rundll32.exe and DLL Files
Almost all applications need to make use of various Windows dynamic link library files. These library files allow applications to call Windows specific functions for different Windows system functions.
Displaying windows and other objects for a graphical user interface.Playing sounds using the computer’s audio driver and hardware.Transferring inputs and outputs from hardware like the keyboard and mouseStoring information in system memory.Accessing any accessories connected to your computer.
There are multiple DLL files located throughout the Windows operating system, but none of those libraries can be accessed without going through Rundll32.exe. The process serves as a gateway for all applications to access those libraries.
How Rundll32.exe Works
Applications call Rundll32.exe each time that application needs to access a Windows library function. The following is how that process works. Every time an application launches Rundll32.exe, you’ll see a new instance of that process show up in Task Manager. Each instance has four main parameters that help the application and the operating system keep track of the process.
hwnd: The handle (identification ID) of the window your DLL createshinst: The handle of the process instance launched by your DLL calllpszCmdLine: Command line used to launch the DLL librarynCmdShow: Describes how the DLL window should be displayed if there’s an associated window
If you see multiple “Rundll32.exe” processes in Task Explorer, this is normal. A new Rundll32.exe process gets launched every time another application calls it.
Common Rundll32.exe Errors
The most common error related to Rundll32.exe is a Runtime Error. This usually occurs when poorly written application code closes the application without properly terminating the Rundll32.exe instances that it previously launched. This error won’t cause any problems with your computer. However, once you reboot the computer, it will kill all launched Rundll32.exe threads and clear the memory used by them. However, malware sometimes causes Rundll32.exe errors in a couple of ways.
Malware installs virus files that are named the same as Rundll32.exe. You won’t recognize the virus file when you see it, but antivirus software will recognize it and clean the file from your system.Malware may corrupt the Rundll32.exe application, modifying the file so that it no longer works properly when applications attempt to call it.
In either of these cases, there are a couple of things you should do to clean an infection that corrupted your systems Rundll32.exe file.
