If you have a Vantec SATA/IDE to USB 2.0 Adapter (model CB-ISATAU2) that suddenly stops working, and Windows tells you that the USB device isn't recognized, check to see if you have a service named "Macrium Service" running. This service is part of the Macrium Reflect backup suite; among other things, it watches for new USB drives to be plugged in. Something about this mechanism interferes with the SATA/IDE to USB adapter's ability to load its drivers. As a result, Windows can't figure out what you plugged in.
Disabling the Macrium Service in
services.msc and then reconnecting your USB adapter will allow your drive to be recognized properly. Once the drive is mounted, you can run Macrium Reflect to interact with it as needed. Unfortunately, Reflect appears to reset the Macrium Service to "automatic" startup mode each time it runs, so whenever you want to plug in a drive with the adapter, check for and disable the Macrium Service first.