Upgraded HP desktop system to Windows 10. Started to have intermittent connectivity problems with my WD MyBook Essential 1 TB external drive. Sometimes connection is fine, other times I cannot get it to connect. The external drive does not show up on file explorer, nor does it show up on disk management. When the connection is good, it is consistent as long as the computer is on. After the computer shuts down, the external drive may or may not reconnect upon computer start-up. I replaced the USB cable thinking it might be a bad connection and the connection was consistent for several days, but now is back to the same intermittent connection.
I’d recommend running a health test on your unit using Western Digital Data Lifeguard Diagnostics and/or WD Drive Utilities for Windows. If the unit fails the test it should be replaced. If it passes the test then I’d recommend contacting WD Support for a power adapter replacement.
The following article is Mac-centric, but steps are the same for Windows once the app is installed.