When an external device is connected to the system, you can see it in the File Explorer window. You can access the device simply by double-clicking on it. However, sometimes it turns out that the device is not available, even if it is recognized, and an error appears.
What causes the error message “A non-existent device was specified” in Windows 10?
There are several reasons for this error. Users who have encountered this problem claim that even a Windows update can cause the error. Basically, if your hard drive has been used for a very long time or it is old, then the resulting hard drive error is a common occurrence.