In most cases if you have a dual video card, you simply
open display properties and under the settings tab you
should see both monitors. You can click and drag each one,
set resolutions, arrangements, designate the primary, etc.
If the second monitor doesn't appear there, Windows
doesn't understand that you have a dual video card or
doesn't understand that there is a second monitor attached.
This usually is a driver configuration issue, and often
happens with the Matrox cards.
Steve Duff, MCSE
Ergodic Systems, Inc.