I've solved it. I did lots of research and discovered it was an easy fix. If I'd had the eyes I have now, THEN, I would've known what to do right away.
It's your Bluetooth radio (as located in Device Manager) that needs updated drivers (that contain A2DP).
Windows has this article which says go to the *hardware manufacturer's website for the updated driver:
https://support.microsoft.com/en-us...l-device-driver-not-found-when-you-try-to-con
*(I for some reason thought Windows was referring to the Unify receiver instead of my computer's Bluetooth radio).
In my case, it was an Intel Bluetooth radio. So I went to intel.com and found its driver download. But that
https://downloadcenter.intel.com/do...reless-Bluetooth-for-Windows-7-?product=59485 Intel webpage said it's best to go to the computer manufacturer's website for the Intel Bluetooth driver.
"About Intel® software and drivers
The driver or software for your Intel® component might have been changed or replaced by the computer manufacturer. We recommend you work with your computer manufacturer before installing our driver so you don’t lose features or customizations.
See
list of computer manufacturer support websites."
So I went to Dell.com and typed in my computer's model number and wallah, there was that bluetooth radio device's updated driver.
My (ETEKCITY Roverbeats) Unify works just fine now.
When Pairing, make sure the Window Bluetooth settings permits it. Here's an article for Windows 7 that describes this in detail:
http://www.tutorialspoint.com/articles/change-settings-in-windows-7-for-bluetooth-device
(though there's that article in Windows help entitled
"Change settings for a Bluetooth enabled device").
Another way of accessing Bluetooth functions and settings is by typing bluetooth in the start menu's search bar and then clicking on the desired choice.