USING THE TPL-406E
Since the bundled software CD will probably have outdated drivers you should head over to the official TRENDnet support page to download both those and the latest available firmware.
The firmware update is done through the Powerline utility and takes less than a minute (as you can also see the reported speed between one of the systems and one of the adapters is 75Mbps).
For extra security you can create a private network under the Privacy tab, you can diagnose potential issues under the Diagnostics tab and also check the current software version in the about page.