That error is generated by the rundll32.exe system file, which is responsible for managing numerous other components. To give us a better idea of which exact program/module rundll32 is having trouble with, please click on the "More info" button in the error message dialog box and post the full and exact text of what you see there.
Alternately, you can look at your system and application logs to see if they contain additional information on the error. To view the logs, open the Event Viewer utility in your Administrative Tools control panel.
"May the Wombat of Happiness snuffle through your underbrush."
- Ancient Aborigine blessing
Please do not contact me by email or PM for help. We're all volunteers here, and only have so much free time to dedicate to our efforts.
However, if I've been working on a thread with you already, and seem to have "forgotten" your thread, please do send me a message. I try not to let things slip through the cracks, but it does happen sometimes.