Getting multiple monitors working again after Windows Vista SP1 upgrade
Saturday, April 5th, 2008
I recently installed the Windows Vista Service Pack 1 (SP1) upgrade on one of my multiple display systems. This particular one is the previously mentioned HP a6110n, in a triple-headed configuration using the built-in Nvidia GeForce 6150SE/nForce 430 video and a generic GeForce 7300 card with two display outputs. The update process runs for a while, including a few reboots.
After the default upgrade process completed, the system was running ok, except the multiple displays weren’t working any more. Specifically, the primary display reverted to the built-in video, and only one of the two displays on the GeForce 7300 was selectable. I tried re-detecting the displays but nothing turned up. I also tried changing the primary display to be on the GeForce 7300 instead of the built-in GeForce 6150SE, which worked, but still didn’t make the second display on the GeForce 7300 turn up in any Control Panel dialogs.
In the end I went to the Nvidia web site and downloaded the latest version of their driver software (ForceWare Release 169.25, dated December 20, 2007). This was more recent than the latest version available in in Windows Update, and appears to have fixed the problem. After installing the updated drivers (and more reboots) all 3 displays were visible from the Control Panel. I did have to select “Extend the desktop on to this monitor” again in Display Settings to get the displays to work, but both video graphics controllers and all three displays were visible from the NVidia Control Panel immediately after updating the driver software, which was the main problem following the Vista SP1 upgrade.
At this point the multiple monitor configuration seems to be working correctly. I observed some problems with random display swapping while I was in the middle of updating drivers and changing display settings, and during the first day or so after updating the system. The primary display would spontaneously move from one monitor to another, or one monitor would become disabled and any open windows would jump to another monitor, but things have settled down now.