I uninstalled FSX and start all over. With the disk 1 there was an error reading the disk. Then I copy one by one file & folders to my D: drive and made sure the size of the file is the same as the copied one.
I then hit DVDCheck.exe and it start the installation. I waited until it ask for disk 2. But it first want D2Feat-10.cab. I then copy al the D2*.* files to the folder from Disk 2. It went on with the installation and then ask for Disk2. I insert the disk in the dvd drive but it would not except it. I then copy all the other files except for the DVDCheck.exe from disk 2 to the folder and wait.
A little later the installation finish with the message installation was successful. It open FSX and the activation window came up and was activated successful.
So without editing the registry FSX is now installed and running. I did a four hour flight and all went OK.
Thanks for the help but I solved it in another way. Maybe there is someone who can follow this procedure and install it successful.
Arrie