This weekend I was motoring down from Frankfurt (EDDF) to St. Maarten (TNCM) in the PMDG 744 (FS9, I will be switching as soon as I convince myself that installing FSX won't screw up FS9). Anyway, here I am at 37,000 feet, and I decide to do a systems check by pulling up the various systems, I hit the fuel page, normal, I hit the hydraulics page, normal, I hit the eletrical page, normal, i then go to the ECS page and suprisingly, the valve between the 1st and 2nd pack is amber and indicating it's closed. I am not using the PMDG failures. I then check the overhead panel for the pack switches and they are all on, I don't think this is a huge problem but I figure I should try to fix it before it get's worse. I was able to fix it by cycling the pack switches on/off one at a time. I thought it was a pretty cool random problem eventhough I don't have the failures enabled.Richard Bansa

I've run FS9 and FSX together for years without any indication that there was a problem. I don't know why you are concerned. You can't run them at the same time.

Same here... FS9 and FSX happily reside on the same box, just on different drives...No issues whatsoever... I can fire up FS9, do a flight, land, shut down, close FS9, fire up FSX, do a flight... no issues at all in over 1 year now...If your PC can hack it go for it...Andrew

OK guys, you've sold me... I will go ahead and install FSX, this weekend. I do have a separate drive available, so I'll make sure to install it on that drive. Thnx!!

The problem happens when you uninstall FSX with FS9 still installed. It can hose FS9's registry entries. I've had it happen numerous times.

Free FS registry checker and repair tool:http://www.flight1.com/view.asp?page=libraryBTW:Both FS9 and FSX FUIPC installers now look for registry entries for the path. If not correct and you don't accept it eventually the installer comes to a choice where you can browse to your FS root folder. Be sure to check its suggested path before clicking OK.