Provided are an apparatus and method thereof for displaying video signals on a display screen of a display apparatus, wherein the video signals are received by the display apparatus from a plurality of input sources. The method includes: determining whether a medium input from a first input source of the display apparatus is in a loading process; if the medium is in the loading process, displaying in a sub-window on the display screen a video signal output from the first input source of the display apparatus; if the medium is in the loading process, displaying in a main window on the display screen a video signal output from a second input source of the display apparatus. The video signal from the first input source may be downscaled and transmitted to the display device so as to conserve resources in both the first input source and the display device.