You can download NI License Manager from this link:
NI License Manager Download.
Additional Information
NI License Manager is installed automatically with any NI software that requires a license to work. If you are installing licensed NI software, you do not need a separate installer for NI License Manager.
You can update NI License Manager by downloading and installing the newest version available. Deleting of older version is not necessary, it will be updated automatically within an installation.
Once NI License Manager has been installed from another software's installer, you can open it by going to
Start>>All Programs>>National Instruments>>NI License Manager. Here you can view the licenses you have available for all NI software.
If you use network licenses in NI License Manager, you do not need to reconfigure the Manage Volume License Server. The settings keep up after upgrading.