A method for configuring resources in IA-32 computers enables the PCI memory address range to be reclaimed with minimal loss of available physical memory. The BIOS establishes a remap window at the top of physical memory. The remap window corresponds to the PCI memory address range. The BIOS reports to the operating system that a portion of the remap window is reserved. The reserved portion corresponds to the AGP aperture within the PCI memory address range. The BIOS reports the remaining regions of the remap window as usable memory. All of the PCI memory range except the AGP aperture is thereby successfully reclaimed for general use.