We can not get the white closed caption boxes off

You either have a CC button on the original remote, which you seem to have found for standard def captions usually white on black, or it is hidden in a menu for settings or preferences. Try your manual or scour your menus. HD does not transmit the codes for standard NTSC CC, so the set must create those itself. You may even find there is a choice of color, font, and size for HD shows--I like yellow with a transparent background as the least obnoxious. -Ken

Hi, if using a cable box, make sure the CC is not coming from the cable/satelitte box.
look through the menu with the other remote