My machine operating Windows 8 is dropping and reconnecting USB drives just after about every second startup. It happens if I have more than 1 connected. It does not happen out of the blue when using the system, only after startup, but renders me unable to use the PC until I gat to the USB port and manually reconnect both drives.
After I log into the system, Windows starts flashing File Explorer windows for both (or three, four...) new found USB drives but closes them instantly, because the drives are dropped and forgotten. This repeats ad infinitum, resulting in flashy screen discotheque of madness.
My primary drives are 750 GB MyBook (quite an elder, but with own power adapter and good performance record so far, NTFS formatted) and 500 GB MyBook Passport (without adapter, also NTFS). The problem persists even if I replace them with two USB flash drives of any capacity.
I thought this strange problem might be caused by insufficient power in the system as I tend to have about 10 - 15 USB peripherials connected (including sound cards, wireless desktop peripherials and printers), but after some experimenting, it does not seem likely as it happens even with minimal configuration (eg. mouse, keyboard, soundcard only).