cpu upgrade

I have a Dell desktop Optiplex 7010.   It had a intel i5 3540 processor.   I have an Nvidea  (GEforce) 1650 graphics card and 16gb of ram installed. 
I have the disk version of FSX (not steam).   I also have the ORBX scenery upgrades.  With this config, everything ran without running out of memory.   

I upgraded from the intel i5 to an intel i7 3770 processor.  (note by BIOS is updated to A29. )   After the upgrade, other computer functions seemed to be working fine except FSX.   Note that Dell shows that the i7 3770 cpu is an option for the Optiplex 7010.   

However, now, shortly after takeoff, the computer freezes and a diolog box says I am out of memory.  I would have thought the upgraded CPU would improve performance-not make it worse.   
Any help or advice would be greatly appreciated!!
Thanks
STeve