To fix this, open Regedit and navigate to this key:
In the right-hand pane, double-click on the (Default) value and delete whatever is entered there, leaving it blank. Click OK. Now perform exactly the same step with the key directly underneath, namely
Once both (Default) values are empty, OE will open normally
If you are happy to enter your registry the above should fix your prob for you.
The sensible thing to do first would be to make a backup of your registry first then procede with fix, good luck....