Toshiba Satellite Z30-A - Manual (Page 101)

To open the Screen Resolution dialog, click Desktop -> Desktop Assist -
> Control Panel -> Appearance and Personalization -> Display ->
Change display settings.
If you are running some applications (for example a 3D application or video
playback), you may see some disturbance, flickering or frame dropping on
your screen.
If that occurs, adjust the resolution of display, lowering it until the screen is
displayed properly.
User's Manual 4-34