I've successfully completed the re-installation of FSX via disks 1 and 2. The product was successfully activated for my computer (I got the option to input the product key). The problem occurs when I try to install the Acceleration disk (I might add that the option to input the product key for the acceleration disk was not seen). The following message pops up in a box when I finally run the software:

We're sorry, an unexpected error occured which is preventing product activation from being completed.
ERROR CODE - 1-80004005
More information on this problem may be available online. Would you like to view this information now?

The online link leads to nowhere when I press the YES button. I also noticed that the FSX icon does not appear among my background icons at startup. Can anyone explain how I can get around this and complete the activation of my software with acceleration disk?

Try this!  Be VERY aware of the letters in PartMgr that need to be capitalized.

 

1. run regedit (Windowskey +R)
2. Expand the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CURRENTCONTROLSET\CONTRO L\CLASS\{4D36E967-
E325-11CE-BFC1-08002BE10318}
3. After you find the folder, double-click Upperfilters on the right side.
4. Change the value from 0 to PartMgr and/or remove any other settings and then click OK.
5. Close Registry Editor
6. Start FSX/Accel and you should get the registration wizard.
 

In my case the value was already there but was listed as PARTMGR (all caps).

It must be changed to read PartMgr