My PMDG 737NG seems to have become unstable. Can I re-install it over my present installation, or do I need to uninstall it first?I have the 800-900 with the temporary patch.Tnanks Gabriel

Gabriel-Here is the best procedure:1) Go to our site and download the REMOVE TOOL from the downloads area.2) Run the remove tool and be sure it detects the proper version of FS....3) After running the remove tool, go into FS/AIRCRAFT and delete the PMDG 737-800/800-Winglets/900 directories. (new remove tool coming soon to handle this step automatically...)4) Run the 737-600/700 installer.5) Run the 737-800/900 installer.6) Run the temporary update.Then you should be in grand shape.... If you have any problems with MSFS immediately after doing this- it is most likely the result of your FS9.cfg... MSFS gets "twitchy" sometimes when adding/removing large file groups- but this is easy to fix.... Delete your FS9.cfg and let MSFS build a new one!

Robert,Thanks for your reply. I'll do as you say.Gabriel