Hi,
Opening up an old topic here.
Can someone tell me why I cannot play DVDs on an external monitor?
I have Windows XP with a Radeon 345M Adapter.

I can run other applications on the second monitor with no problem.
When running the second monitor as primary, the DVD program shows, but
with a blank screen where the video should be. The DVD plays normally
on the primary laptop screen. This is the same with Windows Media
Player or InterVideo WinDVD (I prefer this one)
If I run multiple monitors and move the application to the second
monitor, it stops the DVD. I have not been able to get DVDs to play on
the secondary monitor in any way.
Help is appreciated.
Regards,

Adam
David Winter wrote:

In article <1108528790.371604.62020@g14g2000cwa.googlegroups. com>,
kungfuadam@hotmail.com writes
It's because DVD video is displayed using a hardware trick called
Overlay. The video picture is not really part of the windows desktop, it
is added in by the graphics card, and many cards can't do it on the 2nd
output. On some cards there are options to select how the overlay works
which you would find by right clicking on the desktop and going to the
Settings->Advanced tab. Look for "overlay" settings, on my video card
you have to go down about 3 windows to get to it.

You often get the same problem when trying to connect a laptop to a
video projector, the video is shown on the laptop screen but not on the
VGA output socket; you just get a black box there. On a laptop if you
cycle the display output settings so that the laptop's screen is
disabled and all the output is sent to the VGA port, this often makes it
work.
--
Tim Mitchell

I was able to resolve the issue by simply changing the primary source.

For ATI chipsets- this article is helpful:

http://www.weethet.nl/english/video_pc2tv_ati.php

I had the same problem. However, I found that I could view a DVD on
both screens at the same time if I used Cyberlinks PowerDVD software.