Had the same problem did the following two things , the disk chatter went away and the reinstall of FSX went smoothly:
1) I cleaned the surface of all disks with alcohol
2) Went to Control Panel in WIN 7 - Go to Hardware and sound -Autoplay options
Go to the Software and games tab - Make sure the selection is "Install or Run from your media"
After these steps the disks loaded and ran fine.
I suspect the main factor was cleaning the disk surface.