When you Uninstall the "FSDT Universal Installer" from the Control Panel, the registry key that stores the Addon Manager location is cleared, so you'll be free to choose a new install location for the Universal Installer, the next time you install it.
Unfortunately, by removing the Addon Manager folder, you lost its Uninstaller .EXE, so that process won't be executed anymore. To fix this:
- Download and install the current FSDT Universal Installer, it will still go in the original folder, but that's not a problem.
- Uninstall the FSDT Universal Installer, so it will clear the registry.
- Reinstall it again, you'll be now able to select a new destination for the Addon Manager.