I can not remember where I saw it but at one time I saw something that after installing new hardware that you should back up the old fsx cfg(in case anything goes wrong) and then delete it and let fsx build a new one. I just installed a new video card (nvidia GTS 450) and sound card and these solved a lot of problems I was having (stutters and staticy sound) and was wondering if I should do this. Thanks for any advice.