3T external hard drive: one of two not seen

Portable Drives My Passport
1

I bought a second 3T external hard drive to backup the first one.

The drives are identical 3T external WD drives.

Either drive, when it is the only drive plugged in to either my HP Desktop or my HP notebook computer works with no problem.
However, when adding the second drive to the computer, it is not seen.

How can I copy the contents of the old drive to the new drive?

2

Additional info:

Both desk and laptop are quad core PCs running Windws 7 64-bit version.

Again, either drive when it is the first one pluged in is seen, and when adding the second drive, the second added is not seen.
Plugging in to the same or separate USB controlers does not make a difference.
(Both computers have USB connectors operated by different controllers. The Notebook has two 3.0 and two 2.0 USB ports, the desk computer has three separate USB controlers, each controlling 2 or 4 USB ports.)

3

It’s a Windows problem this post explains how to change it  http://community.wdc.com/t5/Other-Externals/Problems-with-having-more-than-one-USB-2-0-WD-2-TB-Elements/m-p/285728#M4260 A quick fix is just assign them different letters and put them obth online.

Joe

1 Like
4

Thank you Joe S!
It was a minor headache following the very detailed step-by-step instructions at the link provided, but it worked!
I’m glad I had one computer to hook the drives to while I used the other computer to read the instructions on the internet.
I would have never remembered all the steps involved in going into DOS to change the drive’s unique signature number.
But yes, the problem was that the identical drives also had identical “unique” signature numbers!
I changed the final digit in one of the drive’s unique signature number from ‘6’ to ‘7’, and suddenly Windows could see both external hard drives.
Thanks again!

Pete