The following is from Casey (Sent to me by email). You must follow these instructions carefully to uninstall and install the newest version correctly. (Thank you Casey!!)
1 .Download the latest build from the FSS store...go to "My Account" ReDownload the program, it will be the updated version.
2. Double and Triple Check that your current version is installed in a sub directory of program files.
NOTAM!!! IF you have installed DX10SceneryFixer into your FSX directory, then do NOT UNINSTALL. Start at Step4 and install the new version into the default location.3: Open your current version of the "Fixer" and select "uninstall libraries" - if you run FSX using multiple user accounts follow the instructions in the manual!
3: Go to Windows Control Panel and "Programs & Features" "Uninstall a program" and select DX10 Fixer and uninstall
3a: Reboot computer
4: Select the latest version of the installer you just downloaded and "Run as Admin".
5. Enter license if prompted.
5a Do not close the wide splash window, it will close itself
5:Reboot Computer
6: Right click the Fixer icon that should be residing on your desktop, and select advanced, tick the box "Run as Admin"
7: Reinstall the libraries in the fixer and check your other options.
8: Run FSX and make sure all is good.
You can get all the details about the fixer straight from Steve on his BLOG:
https://stevesfsxanalysis.wordpress.com/