. This external drive never did this on my laptop, but once that stopped booting and I began using an older desktop with Windows XP, for some reason the drive keeps acting like the USB connection has lost connection, then reconnects automatically. If I'm using it it doesn't do this, only when I leave it idle and unused after a short amount of time. Here are some possible reasons for a WD hard drive not recognized: A hardware problem (damaged components such as a scratched platter or a failed headstack) File system corruption of the hard drive partition. Issues with a hard drive partition. Insufficient power supply to the WD hard drive. Windows is unable to allocate a hard drive letter.