Check-in to Your Profile > Select product > Customer Support > Search KB or Submit New Ticket and enter 700 in option C.
You will get the following KB Faq and click on the link to the FSX/FS9 Registry Repair Tool. I did not provide the link in my reply.

Q: How to fix your flight simulators registry path in FSX/FS9 (avoid "Your Path for Flight Simulator Files is Not Correct" message in TCE/ACE) (by JB)

A: Use this free FSX/FS9 Registry Repair Tool (36KB)

From: General / Tips and Tricks (QID 700)

See if that helps.

Mark