Cannot activate extended desktop with multiple monitors

[Guest]

I have recently re-installed (clean install) Windows XP Pro on my machine. I
use a GeForce FX 5200 gfx card with TV-out and I used to have the option to
turn on extended desktop and also to use DualView, clone etc. I had my TV
show fullscreen overlay so I could still access my desktop on the main
display.

After re-installing, the device manager only shows one monitor where it used
to show my monitor and 2 'unknown' monitors and I was able to use all the
extended features.

I have tried both the supplied graphics drivers, the newest Nvidia drivers
and some older versions of those with no luck. The drivers work fine, my TV
is recognized and I can swith between the TV and the monitor without any
problems.

The problem seems to be that Windows only recognises 1 monitor and beacuse
of that, doesn't turn on the extended desktop feature.

I have tried installing the same windows version on my other PC with a
built-in graphics card with TV-out and it works just fine on that machine.

Any ideas? Is it a bug in XP or maybe I shouldn't have installed SP2 until
everything was working?

 

[pjp]

XP Pro clean install then SP2 using a Radeon 64 DDR VIVO and a Matrox
Mystique 220. Everythings working fine, tv in and out with Radeon and
extended desktop onto Mystique all at same time (tv in OR out, not together
so can't do a loopback .