I think this mainly goes out to Dave as he knows how, not that I am saying others don't but that's what I know.  If you know then of course chip in 

So a chap I know on my fish forum wants to set up three monitors like the way you have done Dave.  He has an AGP card and on board graphics.  This is his MB :

http://uk.ts.fujitsu.com/rl/servicesupport/techsupport/Boards/Motherboards/Fujitsu/D1521/D1521.htm

So Dave, could you tell me how it's done ?  Or even if it can be done with this board ?

Cheers, I'll see if he wants to register here to talk to you about it.

Many thanks !

I think it will come down to:

Does the Mobo turn off the onboard graphics when you plug in a graphics card (some do but I don't know about that board)

Does the AGP card have dual head?

Other than that, with a monitor plugged into all three outputs Windows should see them all and show them in the display properties.

Usually, if what your friend wants to do is possible there's a BIOS setting that determines which graphics adapter initializes first. If the AGP card inits first, chances are that the OBG card won't init at all, and (s)he won't be able to do it. Also, I'm not 100% positive, but it may also be necessary for both graphics adapters to have at least the same GPU manufacturer (e.g. both nVidia, or both ATI). I've never tried to run two cards of different make, so I don't really know.

Anyway, what it all boils down to is that both cards have to initialize on/after boot. If that doesn't happen, then they're out of luck.

Yup agree with Dave, I guess the best bet would be to try it, plug one monitor into the onboard and another into the card, also like Dave says have a look in the BIOS for the first initialise adapter, Its an Intel chips set mobo so it should have the setting.

He could also look in Windows device manager to see if both the graphic adapters are showing.