Hauppauge WinTV USB - Manual (Page 24)

Setting full screen TV mode
Click Display/Preferences/View and then click on the TV Mode tab.
Set Allow Resolution Change.
If you then click on the TV icon on the 32 Toolbar, the application will switch the
VGA mode to the chosen size (using the Windows Quick Res feature), allowing
the image to be viewed full screen.
WinTV-USB Installation and Reference Manual
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