Impossible USB HDD Issue.

Hello boys and girls. About one year ago, my 500GB Western Digital MyBook hard drive died when I unplugged it from my motherboard. It lived a long life. It was time for it to die. I figured maybe a power surge killed it since I didn't "Safely remove the hardware". The computer it died on was built by myself. It was an Asus motherboard and a Windows 7 Ultimate 64-bit OS. I was convinced that my data was lost, so I bought a 500GB Toshiba Canvio portable USB drive in the color black. I plugged it into a rear USB 2.0 port. It was recognized for about three seconds, and then Windows displayed a yellow popup from the bottom right corner of the taskbar saying "The device has malfunctioned". A new hard drive? Come on. I brought it downstairs to my dads Vista machine, and it worked just fine. I scratched my head, and for kicks, I tried my "dead" MyBook on the same machine. It worked! I could see all my data!

After this, I figured it was a bad motherboard. Since none of the ports on the computer were working with it. (Mind you, mice, flashdrives, printers, keyboards, hubs, etc. were all functioning fine on the system). It was ONLY mass storage USB devices that were not working. I waited about a year and built a new computer. New EVERYTHING. Windows 7 OS, Asus motherboard, and all that good stuff. I was so excited to finally be able to use my USB hard drive again. I missed my data. But... It didn't work. It makes the usb "Bee-boop" but will not display in "My Computer". Mice, keyboards, flashdrives etc. are all working on it. But neither hard drive is working. It is not being assigned a drive letter. When I try to assign it one, Disk Management says "Cannot assign drive letter because the window is not refreshed". When I refresh the window, it says the same error still.

I took the 500GB Canvio to my workplace. I plugged it into a USB extension on a machine with the same OS as me. It didn't work. So, I plugged it into an onboard USB port. It worked like a charm! I could add/remove data. I posted a thread on this forum and someone recommended that I get a powered USB hub. So I did. But no dice. It still does the same thing.

I am very confused. The drive works. The ports work. The OS is a brand new install. It's a brand new computer. All the up to date drivers are installed. I don't know where the problem even lies. The drive works on other machines. But not mine. And it's not my OS because it works on the SAME OS at my workplace. And it's not my computer because it is brand new, and everything else is working fine.

Does anybody know?

If you have room in your computer for another HDD, then you would attempt taking the External apart and placing the HDD in there to see if the problem continues. The changes are it is has a SATA drive hookup. I had the same problem put on a HP system. I could hook the external drive up to my iMac 27" and it worked just fine. So I placed into the HP hooking up to SATA, and the darn thing hasn't had a problem since.

Can you hear the drive spin up? (stick your ear to it when you plug it in - no I'm not trying to be funny)

Also, something simple to try;
Open an elevated command prompt
type cmd in start menu > right click cmd.exe run as administrator

>diskpart
>list disk

if you see it by chance (don't confuse it with your main drive)
>select disk n (n is the new number for the usb disk)
> list volume (see what it says)
>assign (will give it a floating letter assignment)
>exit

maybe worth a try.

The disk spins up inside the casing. The light blinks for about five seconds, and then becomes solid. When i execute "List disk" it shows three disks.

Disk 0 = my 931GB internal drive
Disk 1 = my 7701MB flash drive
Disk 2 = my 465GB portable drive (The one that isn't working)

But when I select the disk and "List Volume" it does not display :/

I have the same Hard drive and some times when plugging the HARD drive in the drive needs to be assigned a drive Letter, I only use this drive to back up my C drive,

I use Paragon Partition Manager™ 2010 Free Edition simple and works great, though you can do this in windows without other software with Disk Manager

Unfortunately I get an error when assigning it a drive letter in Disk Manager.