The below error may come up when you boot up the computer or when you open an application.
Here is how you will solve this.
Go to Start >> Run >> Type Regedit and hit enter.
This will open the windows registry.
Expand: HKEY_CURRENT_USER >> Software >> Microsoft >> Windows >> Current Version >> highlight Run >> Delete the value which includes "rundll" and delete it.
Reboot the machine.
If you do not find this under HKEY_CURRENT_USER try the same location under HKEY_LOCAL_MACHINE.
Let me know if this was helpfull :-)