Try to launch BirdieSyncSetup.exe with "Run as administrator" (right click on the file and select "Run as administrator"). Then if it works, at the end of installation EXIT BirdieSync (menu File/Exit) and launch it again (Windows Start Menu/All programs/BirdieSync/BirdieSync).

It is important to EXIT BirdieSync at the end of the installation to avoid running it with the administrator account and store preferences in the incorrect user account.