The Windows XP tool Tasklist can be used to determine what program modules are currently being executed by rundll32.exe. (For discussion of Tasklist, go to this page.) To create a list of running tasks, open a Command Prompt window and enter the following command:
tasklist /m /fi "IMAGENAME eq rundll32.exe" >C:\rundll32.txt
This will create a text file rundll32.txt on the C: drive that lists the running modules. If you prefer a different location for the text file, modify the command accordingly. Also, to simply view the running tasks in the command window, omit the part of the command that does file redirection, >C:\rundll32.txt.