Setting IRQ manualy

I wish to change my IRQ numbers for intergrated devices as my main board is only pnp and i have no point within the bios to disable pnp and manualy set these up. i am able to do this in 98 but not 2000 and XP, i know that 2000 automatically does this but i am having problems when using flash any idea’s appreciated. when trying to do it in device manager or system console the option to change these settings is always greyed out