the big answer is....maybe.i have a dual boot system with xp pro and win2k pro,and i can run p4/PP from either of my OS's,allthough it is only really "installed" in XP...poser seems to be pretty much self contained once it's installed,i don't think it depends on any outside registry entries...that's P4 tho,i dunno about p5...that said XP is vastly better at just about everything compared to 98...especially once you turn off all the glitz and make it look and run like the windows 2000 system that it is beneath all that crap