Hi,I did a search and read through various threads, and didn't find a solution other than "Run Windows XP, not Vista." Well, I am running Windows XP :)This is a brand new, fresh install. MSI P35D3 Platinum Motherboard, Intel E8400, 4GB DDR3 RAM. I just built the machine yesterday. It has a slightly older Sapphire Radeon X1900 XTX for a video card.FSX is installed on its own drive, with the following addons, and nothing else:Ultimate Terrain X - USAGround Environment X - USAFlight Environment XActive Sky XFSGenesis US National LandclassPMDG 744 FSXLevel D 763 FSXFS2Crew for Level D 763FSUIPC 4.25Other FS related programs are:FSBuild 2.3and if you count CH Control Manager, not running in the background because I do mapping with FSUPIC.Testing stuff out today, I did a flight from KMSP to KATL in the 744. Got to final approach to RWY08L at KATL in autoland, probably about 3 miles out from the threshold when I got the fun and exciting "Out of available memory" error. I know I'm running a fair amount of scenery here, but part of the fun of FS for me is pretty scenery, so I'd prefer not to get rid of any of it.If there's a solution here that I missed (I also checked PMDG OPS) please let me know, I'm up for trying about anything. About all I use this machine for is flightsim.Thanks!-stefan

Hi Stefan,See this post to append your boot.ini: http://forums.avsim.net/dcboard.php?az=sho...8&page=5#405891Ensure you have the latest DirectX: http://www.microsoft.com/downloads/details...&displaylang=enSet your page file to 4096MB or greater.Regards,Jim Karn

You'll also need to install SP1 and SP2 for FSX to be >2GB aware. If you don't install SP2, you'll need to make FSX >2GB aware by following these directions: http://forums.avsim.net/dcboard.php?az=sho...ing_type=searchDisregard the Vista information in that post as it doesn't apply to you.Regards,Jim Karn

Yeah, XP is SP2 with all updates, FSX is SP2, and every other addon is updated to the current version. I'll give the /3GB switch a go, that's new to me. Thanks much for the help, I'll report back if it works or not next time I have time for a flight.-stefan

Out of curiosity, is there any way to tell if it's working, besides hoping you don't have a crash?Also, I was reading up on the userva option for boot.ini, and it looks like it should be set to 2900 or higher, not 2560. Is there a specific reason to make it so low?-stefan

Phil Taylor explains the process here: http://blogs.msdn.com/ptaylor/archive/2007...ress-space.aspx Quoting the relevant section: Note this switch needs to be used with care, since PCI-Express maps the entire address space of the graphics card into the OS address space. If you set the app to use 3G with a 768m graphics card, that leaves 256m for the OS. A better setting is 2560, eg 2.5G, since that leaves 768m for the OS with a 786m graphics card. Much more reasonable.Regards,Jim Karn