Hi. I have an AMD 2500/333 ATHLON XP BARTON CPU in my computer. The motherboard is SHUTTLE AN35N-ULTRA. I wanted to know if this motherboard can be upgraded and if so, what's the best choice? Would I have to do any other changes to the system? I currently have 1Gig of memory (2 x DDR 512 PC3200 DD400). Any help would be greatly appreciated. Thanks.