>Is there any way to change the background of an enabled Checkbox. Setting the Backcolor(and Backstyle to Opaque) only sets the background of the Caption. The square of the checkbox remains in default color.

Can't do that. What I'm doing is to set .fontbold=.t. in .GotFocus, and reset it in .LostFocus, so the user has some clue as to which control has the focus.