There are no drivers that are specific to the BTE40. Like other Bluetooth devices, they are supported by the generic A2DP and HFP drivers for your computer's Bluetooth adapter, which support stereo audio and hands-free audio, respectively.
Unfortunately, these drivers can not be installed through Windows Update, and having Windows completely up-to-date will not ensure that the required drivers are present. Locating the correct drivers will depend on the type of adapter you are using:
• If you are using an external USB Bluetooth adapter, the drivers
should be available at the website of the company that manufactured the adapter.
• If your computer has built-in Bluetooth, the drivers should be
available on the support page for the model that matches your computer.