Ok if i do a slightly complicated toolpath in X5 only in level one, i stall the computer out everytime i regenerate. The computer is a month old and runs win xppro SP3 (i can't use 7 as i have a couple DOS programs) It is a quad-core 2.83GhZ, 3.25GB RAM. I notice when re-generating the CPU usage is only 25%. Is there a setting to use all 4 cores??