Don't store the registry in a dat file. Just store a previous entry in a settings value then get the current value and set it to the settings value every time the program starts. This way, if the user reinstalls, it is detected and auto changed.
The dat files are stored in as files, not registry objects. I used to use My.Settings, but when Platinum Blockland became fragile to it and the settings would be erased each time Platinum Blockland's location was changed (ex. rename directory, move directory, move application, etc.)
Also, what language are you using?
