I recently set up FSX on my new computer and I started experiencing the following problem. After a few hours FSX is not responding and when I close it and restart the flight it does the same thing but this time it stop responding a few mintues after loading at the gate. I run PMDG 737NGX, REX2 + overdive and squawkbox 4. I'm not sure if this problem is PMDG related or FSX related, I would greatly appreciate any help in solving this problem.

I used Bojote's tweaking and tuning tool and followed PMDG's recommendations in the 737NGX introduction manual.