force other resources?

Is there any way to change the grayed out box “use automatic settings”? I read about ACPI and plug and play, but how can you have the option to change it?

I have an onboard Compaq video and I added and ATI Radeon in AGP and they use the same memory!!! but, XP won’t let me force a change. I want to use them both as dual display output.

any ideas?

thx