Robert in CA wrote:
I've tried both #1 and #2 hd's in the 780 and checked disk management
and neither connected. Maybe we should erase both hd's ans re-clone them?

Robert

No line for the external disk in Disk Management (diskmgmt.msc)?

(At least the 780 has no card reader with four entries, to push
the enclosure disk off the screen.)

The Optiplex 780 has USB2 ports. The Windows 7 OS has
built-in USB2 drivers. It should work without needing
any driver work.

The Patriot can be plugged into the 780, as proof something
works. Then Safely Remove. Then unplug it.

Device Manager (devmgmt.msc) may show a yellow
mark, if the enclosure is not being detected properly.

And USBTreeView can show activity as the enclosure
is plugged in. You can start USBTreeView, then plug
in the enclosure and see if an endpoint appears with
config space info.

https://www.uwe-sieber.de/usbtreeview_e.html

Paul