Windows 7 not recognizing Portable HDD

[MattVRX]

Hey guys

Got a Samsung 640gb portable HDD (2.5", USB3) and a few days ago windows on my laptop suddenly decided that it didn't want to recognize it. I can immediately plug it into my desktop and it works flawlessly, diskcheckup reports it's fine so obviously something is wrong with the laptop.
Tried in the USB3 port and both USB2 ports with no success. Tried a generic little 4 port hub in all 3 ports, still reports an unknown device. Uninstalled the unknown device drivers and the USB controller and restarted with no luck, reinstalled the chipset drivers again with no luck.

Has anybody got any ideas of what i can try next, short of formatting the drive and reinstalling windows?

[zirc99]

Re: Windows 7 not recognizing Portable HDD

@MattVRX

Yes, it does happen on some Laptops and Desktops

Possible cause:
External HDD draws too much current, even with its own power supply, resulting in a voltage drop
- 'Unknown Device' in WIN 7 an indication of this. Once this happens, USB subsystem is compromised
and trying other ports (eg USB 2) will not help, unless you shut down and restart

Possible remedies:
Use HDD discreet power supply, if there is one
No point reformatting 640GB HDD - OR Reinstall of Windows
Cut your losses and purchase another Enclosure/Interface (You don't mention it - Is it Samsung or something else?)
They're relatively cheap (Used Inateck, Icy Box)

Bearing in mind:
You don't give a model No. for Samsung HDD - How old is it in terms of technology?
A drive designed for use with direct connection to Laptop power supply, might be too heavy on the juice via USB
Was laptop plugged in or on battery? Desktop will be less prone to this problem

Personal opinion:

For portability and convenience - 2.5" in a neat Enclosure (USB 3)
For critical data and Backups - 3.5" 2TB/3TB w. own power supply (USB 3)