USB External HD not always recognised at startup

I have an external USB hard disk permamently connected to my computer running windows 7. The problem is that sometimes it won’t appear on My Computer and I have to disconnect and reconnect the USB cable.

I don’t have random disconnection problems; once it is recognised it stays put. The problem only occurs some times during startup. It is annoying because I use it for automatic backups with Syncback.

Random guess: Could it be a power issue? Have you tried plugging in an AC adapter or a powered USB hub?

External USB hard drives usually always have their own AC power cable. If its USB cable is plugged into an external USB hub change it to one of the USB ports on the mother board itself (i.e. one on the back of the PC).

I have an external HDD and occasionally Windows just misses it on startup. My PC will show this during the text part of startup (before the Win GUI starts) by displaying:

00 External USB drives detected instead of 01 External USB drives detected

When that happens I cntr-alt-del before the GUI loads and usually sees it the second time.

Check the connections on the cable. Clean them up and make sure they fit tight. Try a new cable.


I’m the computer guy at a local school,and I’ve been having the same problem with some of the USB devices (Smartboards, if you care) attached to the classroom computers. It’s been driving us crazy.

I doubt that’s it. Like the OP, we never lose the connection during the course of the day. The only problem is when the pc is powered up. Sometimes everything goes fine, and on other times, the pc powers up, sees all the devices (including USB mouse, USB keyboard, USB printer) but for some reason it doesn’t see these USB SmartBoards. The solution is simple: unplug it (which the computer doesn’t notice, because it doesn’t realize it was attached to begin with) and then plug it back in - which doesn’t fail to get the computer’s attention.