I appreciate this question is a long shot but here goes.I have a fairly high end computer Intel Extreme X9650 with 2 Geforce 8800 GTX graphics cards in SLI mode, Vista 64 with 4 gigs of Ram. I was getting between 50 - 70 FPS constantly with photorealistic scenery and various payware aircraft. I haven't made any major changes to my computer, but I am now only getting about 17 FPS for no apparent reason. I have checked the display settings and have even lowered some of them but the current FPS does not improve.Can anyone give me an idea what to check that might have caused such a dramatic drop in FPS. I have quite a few addons, I really don't want to reinstall FS2004 again.Glen

Glen,Is the rest of your computer noticeably slower, or is it just FS? Does it start out at 50-70 FPS and then slow to 17, or is it always 17 FPS? One idea: Try checking Task Manager to see if anything is gobbling resources. Hope this further probing helps.Zach

ZachThanks for the helpIt starts out very low. I usually run FS9 in windowed mode so I have quick access to other addons like Active Sky etc. I did switch to full screen mode and the FPS shot back up to 60. Normally there is not much difference between windowed and full screen FPS ?When I first boot the computer Task Manager is showing a Cache of 532 and free memory of 2386, but without doing anything this reverses over about 3 or 4 mins to Cache=3043 and free memory=286, I don't know if this is normal or notBTW I'm running Vista 64Glen

Found the culprit - I had ungraded the free AVG antivirus from 7.5 to 8.0 and it put a thing called 'AVG8 Watchdog' in the services tab of System Configuration. I unticked this and rebooted, now the FPS has increased to about 80 - 90 !!!Glen