I have had a bad day.
Among today's events, the LCD display on my Dell E6500 notebook failed. It had been working with a secondary monitor connected through a VGA cable at 1600x900 resolution until I removed the LCD from my notebook for repair.
Now the max resolution available on the secondary display is 1024x768. If I reconnect the burned out primary display, the secondary monitor is again available at 1600x900.
The video card is an onboard Mobil Intel 4.
How can I maintain the secondary display at 1600x900 with the primary display disconnected (for repair)?
Edit: I just noticed that when Windows boots, it displays at the correct resolution and I can see my desktop in all its glory for a couple seconds then reverts to 1024x768.
Edit 2: I appreciate the answers though they didn't apply to my particular problem. To help anyone with this issue in the future, I ended up using a utility called PowerStrip and was able to force my external LCD to the correct resolution. I can't account for why this occurred. I have since repaired my original LCD, so the secondary displays correctly again without intervention.