How to reset layout to orginal layout. I should get the same layout when first time I installed toad.
@Edit-1: - I dont see SQL editor in the red highlighted area. How we can bring that up ?
Rt-click on Toad's toolbar and show the "Desktops" bar.
Restore your default desktop.
Reset your toolbar layout via rt-click menu over Toad's toolbar.
If you'd like to do a complete restoration to a fresh installed state you can choose the "Copy User Settings..." menu item from the "Utilities" menu.
In there choose the option to reset to a clean state and click OK.
Note that this option will return all configuration settings to a fresh state including removing all saved connections and anything else you have done in Toad. The availability of "Copy User Settings..." is dependent on your version of Toad which I cannot tell from your screenshot alone, but it looks like you're on something in the 11.6-12.7 range so you should have it.