Originally posted by: monzie
......over at DVDRHelp....
For ATI cards:
1) Go into Display Properties>Settings>Advanced>Displays and first of make the PC monitor the Primary Display and the TV the Secondary display, APPLY the changes (and make sure the TV is on and connected). Now set the TV (again in Displays) output to your telly's requirements (either PAL (UK/Europe) or NTSC), again APPLY the changes.
2) Now go to the OVERLAY tab and at the bottom (ignore the pop up info) select the CLONE mode options. When in these additional options select THEATRE (THEATER) mode, Full Screen (or same as source, see later) and your tellys aspect ratio (but even on widescreen TV's keeping 4:3 is sometimes better......you can always use the TV's zoom features), APPLY the changes.
3) What you have now achieved is a hardware (gfx card) derived Overlay (not Windows) for the Secondary monitor (the TV). Play an avi and you will have it on both screens (if you've followed my instructions).
4) Now, depending on you vid files you might not like what you see in Full Screen mode on the TV (eg nasty black bars for non 4:3 ratio files) so use something like Zoomplayer or the Core Media Player to zoom the height and width independently to fill the TV screen (use Same as Source in Clone Options).
5) Now that you have a full screen picture on the TV AND on your monitor you can now use the pc for other things at the same time (without the pc monitor having to play full screen video... or visible at all), bloody useful if the kids want to watch something whilst you get on with some serious work...
For nVidia:
Similar but go:
1) Go into Display Properties>Settings>Advanced>GeForce>nView
Select nView mode: CLONE
Display Pair: Analogue Display (if crt) +TV
nView Display1: Analogue (and CHECK make this display PRIMARY)
On FullScreen Video tab select SECONDARY (unless going thru something like zoomplayer).
HTH
http://www.dvdrhelp.com/forum/viewtopic.php?t=187353