Check the Asus homepage to make sure you download the latest reviosion of the bios flash utility for your mainboard. Usually on older motherboards, the Bios upgrades allow you to accept new CPUs, so that is definitely woth giving a look and seeing if such a utilithyh is available for your specific motherboard under the Asus homepage in their support section.
My OS features preemptive multitasking, a fully interactive command line, & support for 640K of RAM!