PAE is a Windows Function, not a Board or BIOS Function. Also, as I tried to explain, PAE has not much to do with Address Space anymore:
All versions of WinXP except for the x64 Edition now have a hard 4Gb addressing limit, no matter what hardware you use them on and what configuration you choose. All PAE does in those versions of Windows is activate NoExecute support
I don\'t know what else to tell you. Install a 64bit operating system on a spare hard drive and see if that changes anything.