Hi,I have a new custom built PC based on a ASUS 5K MB, Dual Core 6750 processor, an XFX 8800 GT 512Mb graphic board, 4Gb RAM a 675W PS and running XP SP2.I have loaded both Fs9 (+update) and FSX, SP1 and SP2 without any add ons but keep having CTD's on both.I want to troubleshoot this problem systematically but can't help thinking the problem is with the PC not the programs.Could anyone offer any advice on how I could approach getting a stable base installation of both programs?I am not that tech savvy, but can follow instructions....All ideas, help much appreciated.BestSpeedbird217

Hi SpeedbirdI have similar problems. I'm no expert, but have brand new powerful machine which is supposed to run FSX well (and FS9 with all settings to the right), but from the beginning I've suffered terrible freezing with both FS9 and FSX which usually requires a hardware switch-off (doesn't even give me error messages). However the problem improves when using less demanding settings. I can now run FSX with medium settings, and in windowed mode - each time it freezes I lower the settings. I've switched off anti-aliasing. I've also replaced the Nvidia 169.21 driver with the 163.76 Tweakforce version which seems to be more stable on my PC. I've updated all drivers, have used driver cleaners etc. and am defragmenting regularly. I also switch off my ADSL modem and antivirus when running FSX. My PC is erratic and moody with FS - on some days it can run FSX on rather high settings perfectly, then next day it will freeze with the same settings. Could be an overheating problem, as the situation improves after switching off and not using it for some hours.The funny thing is that my PC runs all other software excellently, my teenage son has a wild time with it as it runs Crysis on "high" and other demanding games look fantastic. It's just FS which has been causing me grief (though when FSX does run it looks very well indeed - particularly the Boeing 737 is a great improvement with its moving navigation map). Am hesitant to load add-ons as the system may still not be stable enough, last time it crashed when I tried to load a simple add-on plane. Am still checking out the forums to optimise and further stabilise FSX. If anybody has advice I would welcome it - many thanks in anticipation. My specs:Intel Core 2 Duo 6850 processor, Asus Maximus Formula X38 motherboard, 4 x 1024 MB DDR 800 RAM, 2 x Seagate 500 GB SATA II hard drives (16 MB cache), MSI 8800 GTX 768 MB DDR3 video card, LG 20x Lightscribe DVD-writer, Gigabyte 800 W power unit, Gigabyte Aurora case with 3 fans, Windows XP Home, FS9.1 and FSX SP1, Nvidia 163.76 Tweakforce video driver.