I have an overclocked i7 and couldn't complete one single flight with the 737ngx. 20+ flights and CDT/BSOD every single time, mostly on decent. I was about to give up, but then read something about the difficult relationship between hyperthreading and fsx.Normaly this is managed thru the AffinityMask entry in the fsx.cfg; so i changed the value, but again CTD's every time! So i disabled HT in BIOS and what can i say: not one CTD since then (30+ flights). If you have CTD's and HT enabled: TURN IT OFF!!! This was the solution for me and im so happy because this plane is by far the best and i was about to make a complete reinstall.