How to Kill RUNDLL32

Legitimate or Malicious
Press 'Ctrl,' 'Shift,' and 'Escape' to open the Task Manager. Click the 'Processes' tab, and then right-click 'rundll32.exe' and select 'Properties.' If the 'Location' listed is 'C:\Windows\System32,' then it is a legitimate file. If the location is anything else, it is a malicious file.
Kill Using Command Prompt
Click 'Start,' type 'cmd' into the 'Search' box, and press 'Enter' to open the Command Prompt. Type 'taskkill rundll32.exe' (without the quotation marks) into the Command Prompt and press 'Enter.'
Kill Using Task Manager
Press 'Ctrl,' 'Shift' and 'Escape' to open the Task Manager. Click the 'Processes' tab, and then right-click 'rundll32.exe' and select 'End Process' from the menu that appears.