I've been busy with holiday things, and haven't flown much in the last two weeks. This morning, I tried several framerate-friendly scenarios, and all of them gave me 6 or 7 fps, down from my usual lock of 20. I looked at my log, and the last good flight I had was on Dec. 12. Unfortunately, my last system restore point was Dec. 17. I tried going back to Dec. 17, and it didn't help. I also restored my FSX.cfg from Dec. 12 (which I archive separately) and that didn't help either. I keep a log of changes that I make to the system, and I don't see anything that would affect FSX. What the log doesn't record are Windows updates. (It's also possible that there's an iTunes update in there too.)What should I try? Things that have occurred to me:- Reinstall DirectX- Reinstall Nvidia drivers and set them up again using NickN's instructions.My system: Q6600 @ 2.4GHz, Nvidia 8800GT (512mb), 4Gb RAM, Windows 7 (64-bit).

David, theres a log of your installed updates within the windows update program. On the left hand side you should see "View Update History" and that will give you the updates in date order.Otherwise I would try unistalling the video drivers, and use a driver cleaner before installing the new ones. Also check your processes list within the task manager to see if theres a rogue program taking up 99% CPU or something. (I found a IE process taking up 99% CPU once and that was causing bad frames in FSX).Hope you can get it sorted!

I've seen other reports from other AVSIM members where malware suddenly slows down things. You might run one of the free registry and malware cleaners. I would also rename your fsx.cfg to fsx.old, restart FSX and let the config rebuild. If that doesn't work, then you can simple rename the fsx.old back to fsx.cfg and you have your orig settings back. Just a couple of suggestions and hope they might fix your issue.Best regards,Jim

Thank you, Samwise! I tried the easiest thing first, which was to reinstall DirectX. I wasn't hopeful but it worked -- I loaded up my original flight from this morning, and there I was, back at 20 fps. I still don't know why this got corrupted in the first place. If I had to guess, I would blame iTunes, which also forces you to install QuickTime (and makes it the default player for all manner of media, whether you like it or not). But that's only a guess. Hopefully my hour of panic will help someone else. If the same thing happens to you -- dramatic loss of framerates, in situations that you know should be easy, when you haven't altered your FSX setup, and you haven't messed with your video or sound drivers -- try installing the most recent DirectX end-user runtime package (not the SDK, which is a much larger file).