When I turn on the computer it acts very differently than when I reboot it.

[WinXP Pro, Intel Core2 6600, 2.4GHZ, 2GB RAM, NVIDA GeForce]

Boot:

• Monitor must be plugged into the motherboard or no image.
• Screen resolution 800x600.
• Changes to the resolution cause only the top half of the screen to be usable, and are lost when I shut down the computer.
• Desktop icons arranged in neat rows on left of desktop.
• Nothing of note in system tray
• In Device Manger -> Display adapter: Intel(R) Q965/Q963 Express Chipset Family
• In Device Manger -> Monitors, two monitors are listed
• Hibernate and standby work.

Reboot:

• Monitor must be plugged into the graphics card or no image.
• Screen resolution - 1280x1024
• Desktop icons arranged in the cute circle that I put them in.
• NVIDIA icon shows in system tray.
• In Device Manger -> Display adapter: NVIDA GeForce 6200LE
• In Device Manger -> Monitors, one monitor is listed
• Hibernate and standby do not work.
• When awakened after a hibernation it says:

  The system could not be restarted from its previous location because the restoration image is corrupt. Delete restoration data & proceed to system boot?

Double reboot (inconsistent):

• Monitor must be plugged into the graphics card.
• Screen resolution - 1024x768
• Odd icon shows in system tray whose tooltip says "Intel Graphics"

For a while my morning ritual was to boot, wait, reboot using (alt+ctrl+del -> ctrl+u -> R), wait. Keeping the monitor plugged into the graphics card.

But aside for the inefficiency of this method, I sometimes want to standby and can't.

On the other hand, the computer is unusable when set to 800x600.

Please help, anyone?