APPCRASH util.dll

I am having a problem with my PC hanging during a flight. I have to use CTRL/ALT/DEL to escape and an error message as follows :Problem Event Name: APPCRASH Application Name: fsx.exe Application Version: 10.0.61472.0 Application Timestamp: 475e17d3 Fault Module Name: util.dll Fault Module Version: 10.0.61472.0 Fault Module Timestamp: 475e180d Exception Code: c0000005 Exception Offset: 00006979 OS Version: 6.0.6000.2.0.0.768.3 Locale ID: 2057Additional information about the problem: LCID: 2057I have tried running FSX repair on the DVD and reinstalling SP1 and SP2 but this has not solved the problem. I'd appreciate any thoughts on the matter.Phil