Dual monitors acting up

This is a Pentium 4 running ATI Radeon 9550 card with VGA and DVI outputs to Acer LCD monitors set to Extend Desktop. Only BIOS display settings are for AGP card and card aperture at spec 256mb where it's set. Also this is a 9 year old Best Buy premium house build VPR Matrix which has not run dual monitors before.

The dual monitor setup will not stablize, losing the DVI monitor after it suspends, or faiing to start the DVI monitor no matter which is set as Main, drivers updated, using full software or not, resolutions synchronized, etc.

To get the DVI connected monitor to start requires Logging Off and/or Restarting, unplugging one or the other, fiddling with both for awhile. Then it is stable until next suspend or shutdown.

I don't have enough experience with dual monitors to know what else to try.

I wondered if it was for either/or also until it works really good once I can get it going.

The only BIOS settings for display are AGP aperature which is set to card's spec 256mb, and either AGP or PCI card set to AGP.

Yet in the beginning I was able to get dual monitors to work by resetting BIOS to defaults anyway.

Thanks.

Thanks. Is there a setting in MultiMonitor that might help restart the secondary monitor after resume?

Solved! Here's how:

The Intel Chipset on this old VPR Matrix (Best Buy premium house brand) had 2001 drivers installed by Win7, even though there are 2006 updates. Running the Intel Chipset Installation Utility would not install the chipset until I went through each chipset Device in the Device Manager to manually update them from the Intel .inf file in Programs. It would pick up the driver using either Browse or Automatic.

Hoped this may have solved it when the "Processor to AGP Controller" System driver caused the screens to refresh like it does when a Display driver is updated. It now had 2006 instead of 2001 control of the card. Would it stabilize the Dual Monitor setup?

After the requested restart it started up for the first time to both monitors and has remained stable ever since.

This is a lesson in the importance of updating the chipset and if it doesn't auto-update when run from installer persisting to manually install each driver for IDE/SATA, USB and System controller Devices.

Thanks all.