I've been running Poser5 mainly from an external USB 220G hard drive. I had to leave the actual Poser5 file and a base Runtime folder with the V3, M3, etc. figures' Delta files on my C:/ drive. Otherwise, my "inject" files don't work. I'm upgrading to Windows XP, Firewire connection and from 128 MB to 512 MB memory so I'll really be happy to get my PC back. When considering what size external hard drive to buy, please keep in mind that I only have runtimes and saved works on mine. I bought a 180G (?) hard drive last winter and switched to the 220 G this springs. The drive is already half full!