I just finished upgrading my win2000 to winXP Prof. For S&G's I clocked a render, that under 2000, took 3min 10sec. Under XP, the same scene rendered in 2min 30sec! I couldn't believe the difference, so I tried it again and got the same results. No changes, other than the operating system, were made. This was an upgrade and not a fresh format. So it would seem, that XP is the operating system of choice to run P5. Mark