Did you research this at http://www.google.com/search?hl=en&q=cl+rc+engine3+dummy+winidow
Just so we know if you have covered the usuals.
On a brand new Dell laptop running XP, the error message "cl rc engine3 dummy winidow" appears during every single shut down or restart. This seemed to start right after downloading a spell checker for Outlook Express (because of Office 2007) from Snapfiles. Don't know if this is related or not. We have installed and run CCleaner, AVG, Adaware and Spybot to no avail. What is this problem and what can I do to fix it?