This started after installing 2 other retail A/C add-ons. When I select one of the 744 PAX models, the nav data base screen comes up and loads, then when I select OK to start that flight, the loading scenery objects screen comes up and hangs at zero percent. Cont-alt-delete brings up the task manager, then looking at performance I see that CPU usage is around 74-86% and PF is at 946mb (out of a total of 1 gb. Physical memory shows 159600 available out of 1047548. I have to kill the FS9 process to get out.Oddly, the freighter loads and works normally.Just before the two new AC were added, I also did a system rollback; Kaspersky (trial) didn't install cleanly and I went back to the day before that installation (about 2 weeks ago). I didn't install anything else in that interim. I did notice that after the rollback, I had duplicate copies of some files scattered, apparently randomly, throughout the drive; those files were appended with numbers in parenthesis (xxxxxx.xxx (2), etc.) When I try to load the 744 PAX, I almost get the impression FS9 is trying to load two 744's at the same time and the resource load is too great. I can't, however, find any dupes in that regard.Everything else works fine on FS9.Thanks for any help.Dave Skuback

I am having a very similar problem as you are. My fs hangs whenever I load up the 737 or 747. What would be the cause of this. I have reinstalled the aircraft multiple times yet it still hangs.

I had the same problem until I completely uninstalled FSUIPC(text file, key, etc) and then reinstalled it. After that everything worked for me. Also, not sure if it's true, but I heard multiple times if you have the 737NG and 747-400(F) series, you need to install the 737NGs first, then the 747-400 aircraft. Not even sure if that would be related to your problem or not, but I'd try reinstalling FSUIPC first since it would be the easiest.Ken Hopsin

EXACT same problem on my end. Other aircraft load fine. I've only tried the PAX 744. Similar issue as you - I recall doing a WIN XP Rollback recently to try to correct an issue I was having with iTunes. When the rollback didn't correct my problem however, I went back to the state prior to the rollback. I hope someone can shed some light on this.Regards,

O.k. I found the issue that fixed this problem for me. If you guys don't have FS2CREW you may want to stop reading here - perhaps I just got lucky on this!I went into my FS9 directory and sorted the files by date. I noticed that my Scenery.cfg file was updated along with an FS2Crew .INI file for the PMDG747. Well, the Scenery.cfg file was updated after I installed the latest FS RealTime program. I also recently updated all my FS2Crew software versions.I remember the install of the update specifying that I go to the FS2Crew Control center and save my config. I went back there and noticed that my configuration was set to USE FS2Crew. Not something I normally do. I changed it back to my original PMDG panel by selecting the button and presto - things started working again.Aaron