I haven't used Poser 6 yet, but I do know a thing or two about upgrading computers. First, definitely upgrade your RAM. You can get a 1 gig RAM for about $90. Cheaper if you use SDRAM. You'll definitely want to go beyond the 512MB border. Second, your Dell has 2 hard drive slots so putting in more hard drives may be kind of sloppy. Hard drives don't need to be screwed into hard drive bays, that's just to keep them secure. However if your tower doesn't do a lot of moving, mine doesn't... at least I don't think it moves around when I'm not here... then it won't be an issue.