If you change some settings by mistake, you can undo those changes easily as long as you haven't updated the server yet. From the Edit menu, select Undo, or click the Undo button on the toolbar.
As long as you don't make any new changes, you can also redo changes you've just undone. The Profile Editor remembers the last 20 changes. To abandon all changes, from the Profile menu, select Reload.
When you update the server or exit the Profile Editor, the undo and redo buffers are cleared.