Can't start FSX

The application has failed to start because its side by side configuration is incorrect.

Indicates Microsoft Visual 2005 w/SP1 and Microsoft Visual 2008 w/SP2 are improperly installed or not even installed. See page 6, AVSIM CTD Guide for proper versions and more information. You also need Microsoft.net 2.0 (at the minimum).

You can download the latest versions of 2005 and 2008 here - http://support.microsoft.com/kb/2019667 . Make sure it is Microsoft Visuals C++ and NOT Microsoft Visual Studio. Microsoft Visual 2005 is used by Microsoft to make sure FSX and FSX/Acceleration are installed properly. Microsoft Visual C++ 2005 is installed when you first install FSX if it is not found on your system. Microsoft Visual C++ 2005 w/SP1 was suppose to be included with the Acceleration upgrade but Microsoft forgot to include it so everyone is required to download the SP1 version manually. Microsoft Visual 2008 w/SP1 is not really need for FSX/Acceleration but used by many addons.

I think you would be wise to completely uninstall FSX and all of your addons and start over. It might be a good time to reinstall Windows too. The fact that your error report indicates you have the basic FSX installed and later versions of FSX installed indicates to me to be massive corruption.

Best regards,