Initially I was very reluctant to add to the massive number of posts, with yet another"TRY THIS - IT WORKED FOR ME" type post. However, it did work for me, and it does seem to have some logic to it, so here goes.It should not do any harm, and might well be a solution for others. ----------------------------------------------------------------------- PROBLEM: General Instability, random crashes, etc etc MY SOLUTION: Re-Install only the VS C++ 2008 Libraries that PMDG want to install. PRE-CHECK:Look in (xp)"add-remove programs" / (W7)"Program and features" You should only have 2 Microsoft Visual C++ 2008 Redistributable - x86 entriesone Version 9.0.30729.17other Version 9.0.30729.4148 THERE SHOULD BE NO DUPLICATES with same version. !!! ( There may be some C++ 2005 and/or C++ 2010 ones, IGNORE these) If you have any different C++ 2008 version, or duplicates, the proceed with SOLUTION(If all looks ok, this solution is NOT for you) PROCEDURE:(1) Uninstall PMDG 737NGX (2) Uninstall ALL C++ 2008 X86 redistributables,(3) Reboot.(4) Re-Install PMDG 737NGX ( This should add back the two wanted C++ 2008 X86 distributables)(5) Check that they are there as wanted ( see Pre-Check)(6) Re-boot (recommended - why not )If you want to install HOTFIX, do so now(7) Install LATEST HOTFIX only ( Do NOT install previous HOTFIXs first -- seems to be PMDG's recommendation ?)(8) Re-Boot (recommended - why not) CONCLUSION.Worked for me, If you have any C++ 2008 X64 Redistributables installed, its probably for some other 64 Bit application. LEAVE THEM ALONE. DO NOT un-install them.Nothing to do with FSX .. FSX is only 32 bit application. REASONING:Microsoft recommend un-installing old versions of the C++ Library, ( for a given VS Version), before installing an updated one.It looks as if the PMDG installer is only checking to see if you have the C++ 2005 versions that it thinks you should have, and if it does not see them, it is installing them, WITHOUT uninstalling the old versions ?Certainly having two entries of the same version library does not look right !!! ------Once again, do this at your own risk. I have taken the time to explain my reasoning.My reasoning and assumpotions about the installer may not be 100% correct, but it did work for me. Good luck Geoff

found duplicated entries, will do the removal and start all over again. Thanks

Hmmmm... I only have one of the two 2008 X86 libraries, the .4148 one on a WinXP 32 bit system. Wonder if that is normal. Guess I will leave mine alone for now.

Hmmmm... I only have one of the two 2008 X86 libraries, the .4148 one on a WinXP 32 bit system. Wonder if that is normal. Guess I will leave mine alone for now.

That is what I would expect to see, just the latest version. However, when I had removed all my c++ 2008 x86 libraries, the PMDG installer, definatly installed TWO version of the library, one after the other. Not too happy about that ( do not fully understand why it would), but if thats what it does, then I will live with that and see what results I get,. Later, I will be tempted to remove the lower version one, and see what happens (after a little more research) Geoff

That is what I would expect to see, just the latest version. However, when I had removed all my c++ 2008 x86 libraries, the PMDG installer, definatly installed TWO version of the library, one after the other. Not too happy about that ( do not fully understand why it would), but if thats what it does, then I will live with that and see what results I get,. Later, I will be tempted to remove the lower version one, and see what happens (after a little more research) Geoff

Ok, so what if neither were installed after installing the NGX?

STOP. This is incorrect information. Those other versions of the VS runtimes sit in the Windows\WinSxS (side-by-side cache) folder and are directly used by applications that require that specific version of them. VS runtimes do not work like normal program versioning does where only the latest one is required. You can find this described on multiple MSDN pages, Microsoft help forums etc. If a program is written in Visual Studio using version 9.0.whatever of the VC++ 2008 Runtimes, then that's the exact version that's going to get installed by the installer and it's what the program looks for when it runs. Programs look for different versions based on what they were programmed with through something called the application manifest - the WinSxS system directs it to the correct dlls. This is very dangerous to uninstall all the versions of the runtimes that are installed - you're likely going to end up with applications that don't run correctly because they're now missing the specific runtime version they were programmed with. I have a ton of different versions installed myself and I do not get crashes or anything else with the NGX. This is a bogus "fix".