Memeory, chip speed, and hard drive. The bigger the better. XP or Win2000. Why? Because Poser doesn't use hardware acceleration, and is terribly memory intensice. The more memory you have, the better it will run. You need Win2000 or XP becuase both ME Win ME and 98 have limits on the amount of memory you can use, and you'll waste most of the memory if you use them. Big hard drives help because of the swap file. P5 likes continuous space available, so you need a large area available for swap. Add to that all the files you'll wind up with. I've got 20 gig in compressed files just for Poser. I'll be getting a P4 fast machine with 2 or 3 gig of memeory next month, 2 120 gig hard drives. I am getting a very good video card with lots of memory too, because Daz Studio will use hardware acceleration. More power, Scottie! I need MORE POWER!