You've said that you've reinstalled FSX. Are we talking about at least FSX SP2? To check, you can click the fsx.exe and post the version number. Should be something beginning with 10.0.xxxx

Your dll.xml entries look correct, so lets assume that the copy protection has locked you out. When you reinstall, are you asked for a code? Did you make sure that it was entered correctly? Mind extra blanks and things, those can mix up the entry and it will install even with a wrong code, but it will never work.

Always run the installer as admin (right click and choosing 'run as administrator') and perhaps disable your antivirus for a moment. Until the installation is finished.