"Not Responding" Problem

[transpower]

I've been using FM 11 Advanced for some time now without an issue.  But with recent upgrades in Bitdefender and Flash, FM is now hanging, and I get the awful Windows message "so and so program is not responding."  I took off Bitdefender 2014 and went back to 2012, and even removed that, but I still get this message on my main system.  I have a backup computer with FM 11 Advanced, as well, and my FM solution runs perfectly on that system, with no "not responding message."  I have run the Windows Memory Test--no problems.  I have run chkdsk /f on all drives, no problem.  I have run the "repair" function of the FM 11 Advanced CD, and even that didn't make a difference.  I have run Recovery on the file, and even that didn't make a difference.  I've run ReImage to restore any missing or corrupt Windows 7 Pro 64 files--and even that didn't make a difference. Can any of you suggest other things to try?  My solution worked fine on my main system up until a few days ago; and it's only the layouts with the most complicated calculations which hang.  The backup computer is slower, but doesn't hang....

 

[transpower]

I couldn't think of anything else to try, so I restored an image backup of my system and then restored individual files (created after the image) from my backup computer.  Everything is working properly now, but I would still like to know the source of the "not responding" problem.  If you have any insight into this, please respond; thanks.