USB device not recognized?

[D€vIL²]

Ok, all my USB ports in the back of my computer are taken up. I have 2 ports in the front and a card reader that had a USB port. Heres a pic: http://img388.imageshack.us/img388/6740/dsc005368mb.jpg

What i'm pluging in is a External HD. When I try to plug it in one of the two lower ports it says it can't recognize it... if I plug it in to the card reader it finds it fine and makes it ready to use right away. Whats the deal? The 2 lower ports obviously work...

 

[Stucco]

I had a similar situation with my external HD. It has firewire & USB connections. I use the fire wire for my PC, but if I'm transferring to another PC that doesn't have firewire, I can just use USB. When I tested it on my PC's front USB's, it didn't even recognise the HD. I knew the HD worked, because I had tried it with the firewire. I knew the front USB's worked, but I tried it in the back one's anyway. It worked straight away. I don't know why.

 

[lanceleader]

If your external hard drive take its power directly from the usb port, that can be the problem because sometime the front usb port don't have enought power. If your hard drive have an external plug for power, I have no idea why it doesn't work.

 

[Stucco]

That's a good point, although I don't imagine that any manufacturer would be dumb enough to make a USB powered device that needed more power than a standard USB port would provide. My HD was externally powered, anyway.

 

[Revisedsoul]

i know mine is like that, requires 2 usb plugs to be put in(came with the proper cable thank god)