I am not the only one whose had this problem: I have successfully installed FSX and FS Accelerator three times. Each time I have not had the opportunity to register my Product Key.  As a result, even though I have been running Accelerator since it hit the market; I am still  running the Demo, getting the ERROR CODE: 1-80004005 which means I don’t have the Product Key registered.  I have tried all of the few “Helps” that I have run into, including the Flight 1 Registry Repair Tool (which did not help) Realizing that I am going to have to resort to the phone installation help for Accelerator from Microsoft, I have been trying to find a number for my area (USA), I haven’t even been successful at that.  There are bound to be a bunch of people out there who have had this problem and may have a solution.  If not, I hope that you can give me a phone or e-mail point-of-contact for Microsoft.  So that I might get on with my FSX life. Thanks in advance.

The number in the pamphlet that comes with 'Acceleration', different from that on the URL Steve gave, is 800 537 8324 (long hold times may be experienced).