I am not sure if this is the correct forum for this information as it is quite important for FSX pilots using Windows 7. I have been on the verge of dumping FSX because of the problem of FSX not responding on a random basis, I could hardly complete a flight where fsx would stop responding, it would return after a period of time providing you did not select anything in FS (on my system 7 minutes), I have trawled the web in search of a solution, suggestions varied from anti virus software, Active Sky, UIAutomationcore.dll and other dll files, all with no success. However I seem to have found the solution and it is so simple it is silly, I have set my frame rates to unlimited, and I have flown over 30 hours with no occurences of the dreaded not responding, during the flight the following software was running Active Sky, Flight Sim Commander, Ultimate Traffic 2 and Flight Logger. I have tried to encourage a failure by running various other packages during a flight ie Mail, Office software, printing and downloading files from the web. Hope this helps any other frustrated FSX pilots with this problem.