Vista does not recognize my Passport External Hard Drive

Hello,

I am trying to get my Passport External Hard Drive data restored. The restoration could not proceed because my Passport disk disappeared off my computer.
I changed USB ports and cables without success. My other Passport works.

The Disk Manager reports the disk is unknown, "not initialized" and unallocated.
The last thing I want to do is erase the files I am trying to save.
I hope someone is out there this weekend to help me. WD Support doesn't open again until Monday and I need to get my restore started.

Thanks in advance,
Barbershop4