Got a fresh install of FS9.1. Ran simply great for two weeks. Last night it simply would not start any more. The splash screen would appear along with the hourglass. After 10 seconds or so the hourglass would turn into a regular cursor and I could see in Task Manager that FS9 has stopped responding. Under Vista 64 I had turned off UAC. FS9 was installed in a separate folder.My other 3D application (Lock-On) runs just fine. Ran a 4-hour memory test - no errors. Reinstalled ATI drivers (HD4850 here). Turned off sound card.Recreated FS9.cfg.Reinstaled 9.1.Disabled all add-on sceneries by manually editing scenery.cfg.Tried starting in Windowed mode.Reverted to the default FS9.exe file. Was using the no-CD over-2GB-enabled executable.Still no luck. Created a dump file. What tools could I use to analyze it?Any other suggestions/tips/ideas are welcome.Thanks

Hi,Exact same thing happened to me this weekend. Tried everything, would have pulled my hair out if I had any. Turned out to be a problem with NTune. For some reason, FSX worked perfectly fine while FS9 would completely freeze at the splash screen. Uninstalled NTune and suddenly, FS9 started up, no problem. I certainly hope this is of some help to you, and if not, then perhaps to someone else who is having some troubles.CheersDennisCYZX

Run something like Orthos, to check up on the CPU. Although I don't think that's an issue.Backup your main FS9 folder, delete registry setting for FS9, install it new. See if it starts.My thoughts are that modules or gauges folder is containing something that might be preventing the start.While you said Vista64, it came to me also, that my Vista32 was working really badly with my FS9, giving it every now and then unexplained crashes, usually a lock up, similar to yours.

Will try different ATI drivers..Don't know if Omega does any for the 48xx series..Thanks guys.