Rundll.exe is a command-line utility embedded in a Windows operating system that is used to run program codes in DLL files.
Each DLL file contains codes that are used by different programs to perform a particular task. The rundll error is generated when a program is unable to access the particular code it requires to complete a specific function.
Cause of the Error
Malware infection is the most common reason behind Rundll errors. Malware programs, such as virus, worms, Trojan, adware, and spyware often modify or delete important DLL files on your system. This causes Rundll errors to appear when programs are unable to access the DLL files infected by malware.
Improper installation or uninstallation of programs or applications may also cause Rundll errors.
In case you notice that you are getting Rundll errors after you have uninstalled a particular program, then to correct the issue first reinstall the program and then uninstall it again through the Control Panel/Add or Remove Program utility. During uninstallation, if you are prompted whether or not to retain a particular shared file, choose to keep it on your computer.
Many Rundll errors occur when you start your PC. If this is the case, perform a clean boot to identify and rectify the software program or hardware device that is generating the error. To do this, perform the steps listed below:
Go to the Start menu, click Run, type msconfig and then press Enter to open the System Configuration Utility Dialog box.
On the General tab, in the Startup Selection section, select the Selective Startup checkbox and one of the options listed below it.
Restart your computer.
Continue this until you have zeroed in on the checkbox option causing the Rundll error.
Next, in the System Configuration Utility Dialog box among the tabs listed in top, select the checkbox option that is causing the Rundll error.
Now, clear all but one command under this tab and reboot your system. For instance, if the error appeared when you selected the Load startup items checkbox, open the Startup tab, clear all but one option on this tab and then restart your PC.
Continue the process until you isolate the command generating the Rundll error.
Resolve the issue related to the identified software or hardware that is causing the Rundll error.
If you believe Rundll errors are appearing on your PC due to malware infection, then install a reliable antivirus suite and perform a full system scan to detect and remove viruses. Also, keep your antivirus suite updated with the latest virus definitions and security updates.
Rundll errors may also occur if the entries related to DLL files in the registry are invalid, corrupt or deleted. Perform regular registry scans, using an efficient registry cleaning tool, such as PCHealthBoost to ensure your system registry remains free from unwanted, obsolete and invalid entries.