When we add rules to the transform repository, by default the RulesLibrary.xml is created at this location, C:\Users\sgolwalk\AppData\Roaming\Quest Software\Toad Data Point 4.0 ( In my case ). This is the application data directory. If you open up “About Box” in Toad Data Point and click on “Application Data Directory” then you will be taken to this location.
I am not sure how did this file end up in the location you mentioned which is C:\Program Files (x86)\Dell\Toad Data Point 4.0. Did you move it for some reason? I would suggest to delete this file from this location ( sorry for the inconvenience ) and then try one more time to save the rule so that the xml is created at the default location. If that does not work then try to delete this file and copy it in the App Data Directory.
Can you please try and let me know if that works?