1 & 3: I have no idea what causes this, but it does sound like a new installation might be the only option... I'm not a software or PC engineer, so maybe someone else can shed a light on this! 2: The limit is entirely in your system, CPU speed and RAM is what counts. I have about the same PC spec as you, and I run into problems if I use more than three characters (Mike and/or Vicky with hi rez textures). Everything in the scene counts, if you have a background wall with a hi rez texture and a huge bump map, it will affect your rendering speed. Same with clothes, which are basicly the same as characters: a mesh with textures. The rendering engine will not notice the difference.