Telling the full story so all the keywords will be included in my response for future searchability:I've been looking everywhere for a driver or chipset info for the unbranded 'Mini HD USB 3.0 HDMI Adapter' for years.
Jun 23, 2014 I have windows 8.1 pro on a Dell Optiplex 740. I have a Fresco Logic USB3.0 VGA Display 'dongle', however I only have USB2-ports, so I must accept I only get 800x600. With the driver which came on CD, it showed up as an A/V Class Device. With the driver from fresnologic.com, it show up a a USB Video class device. Windows 8 and Windows 10 will install the Intel USB 3.0 xHCI driver with the built-in driver, but it will not always work for some USB 3.0 devices. If you reinstall the Windows 8.1 or upgrade the system from Windows 7 to Windows 10 and trying to make the USB 3.0 in function, maybe it will be not successes.