I've never had any problem with fs9 - untill now. I've been tweaking the cfg as you do. Just trying some graphic changes to get a little more out of it. I didn't think anything drastic. And it seemed to be better but all of sudden I find now that it will ctd when I click the fly now button.The sim loads fine. Can access all the options. But just before the a/c will appear, I get a ctd and this : Problem Event Name: APPCRASH Application Name: fs9.exe Application Version: 9.1.0.40901 Application Timestamp: 4135a208 Fault Module Name: unknown Fault Module Version: 0.0.0.0 Fault Module Timestamp: 00000000 Exception Code: c0000005 Exception Offset: 00000000 OS Version: 6.0.6001.2.1.0.768.2 Locale ID: 1033Now I've tried deleting the cfg and started again. At the low resolution and minimum graphics that it seems to default to, the sim runs fine. But when I boost the screen resolution to the same as my monitor, 1680 x 1050 x 32, this ctd, appcrash happens. Kinda strange. Yet only a few days ago all was fine. I havn't added anything differently. And guess who forgot to actully copy my original cfg anyway before I made changes! I wonder if there was a problem somewhere along the line when I changed it originally? Yet for some reason though, at a lower resolution it seems to work.All a bit confusing!Just to add as well, I did try this from the pmdg page but reverted back to what it was originally because I thought that may have been the problem. Or at least I THINK I changed it back the right way!mproving the Windows pagefile Find and read up on the various discussions related to page files. We personally have never had a problem with the page file in windows slowing down MSFS. We guess we're just lucky. Many people have fiddled with their page files and created unintentional side-effect of slowing down MSFS. We recommend setting up Windows to manage the page file - schemes for creating a permanent swap file may have been useful back in the Windows 98 days, but XP is very good at managing it on its own and if you use one of the good defrag utilities above, it will be able to move the pagefile to a spot on the disk where it can't get fragmented and slow down. To set the swap to Windows managed:

1. Go to Control Panel/System/Advanced
2. Under Performance click Settings
3. Click the Advanced tab.
4. Under Virtual Memory at the bottom, click Change
5. Highlight your main drive where the swap file is placed and press System managed size
6. Press Set then press OK
7. Reboot your machine and run an offline defrag with one of the programs above.

I'm just trying all options because i don't want to re-install. Flamin' painfull with all my add-ons!!! Any help here guys VERY appreciated.

Well, I give up. I've tried everything bar re-install (rather have my teeth pulled). I've googled 50 million things that COULD be it but nothing seems to be the same. Stranger still is that I have the FS9 9.1 update but have NEVER installed it. Maybe that's the problem. Probably easier to solve the Bermuda Triangle mystery than this one.