USB Hard Drive Stops Working

I have a USB hard drive that seems to disappear after some time.  It is a SimpleDrive
Hitachi HDT721010SLA360 USB.

Strangely, I found that the system's internal hard drive is a Hitachi HDP725032GLA360; very similar.

I went into the Device Manager, and found a problematic USB device.  I uninstalled, rebooted, and the drive came back.  I believe the error was

"Windows cannot load the device driver for this hardware because there is a duplicate device already running in the system. (Code 42)"

Any ideas?  Tools for monitoring?

Thanks,

- Michael