The present disclosure relates to handheld mobile terminals that implementing methods for a technology of displaying and adjusting sizes of multiple windows on a screen of a handheld mobile terminal. The handheld mobile terminal may be configured to display a plurality of windows together on a screen. Under an edit mode, the handheld mobile terminals may receive a first instruction from a user of the handheld mobile terminal to adjust a target window of the plurality of windows to any size the user wishes; and adjust the size of the target window according to the instruction.