I have a Seagate backup plus 4TB Desktop External Drive on Windows 10. It keeps disconnecting and after a few hrs. or a reboot stays disconnected or reconnects. If I unplug and replug the USB cable it reconnects. Sometimes I get a Windows message on reboot that it didn't recognize the last USB device which was connected. I have switched cables and ports. It is now connected to the main unit. The same problem exists. I ran all the Seagate tools tests on the drive (except for long generic) and everything passed. When it is connected the drive is fast and has no issues. Windows error checking shows no errors. Seagate wants to charge me for Support because it's out of warranty. The drive is clean as I probably shouldn't use it until this is resolved. One other thing, when I unplug and replug the USB cable it usually reconnects. Any help would be appreciated.