Yes, changing it on the Properties palette should make it the new default until the next time you change it. The same holds true for Doors.
If you use Tool Palette tools to place Windows or Doors, you can also specify a value for the Measure to property in the tool's properties. Using a Tool Palette tool with a specific setting will not reset the default value, but will apply it to objects placed by the tool. This is handy if you typically want to measure to outside or inside of frame for nearly all objects, but have a few styles where you want the non-typical value.
David Koch
AutoCAD Architecture and Revit User
Blog | LinkedIn
