Freezing up

When in FSX SE I loaded the PMDG 737 on another flight I loaded the PMDG 777 and on a third flight a payware Heli. After switching to two or three cameras everything freezes. I hear the sounds but the throttle won't even work. The options at the top of the screen in window mode don't work and right clicking won't work. When starting up, the VAS is showing around 331Gb and within a minute it shows around 1.17 that's for both payware and default scenery.