Problems with multiple passports

I am running Windows 10 on a PC with a passport drive providing file history back up. I find that any attempt to attach a second passport drive fails. The drive connects to the USB and can be uninstalled, but the drive is not visible on the system. Attaching it to a different PC also with WIN 10 has no problems and the content of the drive can be seen.'I have attempted changing the names of the drives without benefit.They are useful drives for different purposes. Is there a way around this?

Hello, are they the same drive model? If the answer is yes, then you have what is called signature collision, you will need to access disk management and you should see one of the passports are offline just right click on it and mark it as online.

Thanks Iluna, yes I think they are the same model, and had hoped that
renaming them would work, but it didn’t. Does this problem occur with
all drives. If I were to put several WD Red drives in a machine would I
need to do the same thing?

@wintergreen, did you check Disk Management when the drives are installed? Make sure they are all seen and recognised, and it might help explain why it isn’t getting a drive letter. (if you can’t figure it out, try getting a screenshot of what Disk Management shows, and post it here.)

Hi Thanks for your note. I was not aware of this. I will certainly check
disk management… I think the drive was seen as I was able to uninstall
it, but not see it. It is the first time I have run into this situation.
Thanks for your help