Access data from former hard drive with usb 3.0

[RebelofMars]

I have recently ungreded my hard drive to 2TB from 500GB, however, I forgot to clone sections from the old drive to the new drive prior to shuting down. So, I've had to rebuild my Toshiba Satellite C75-B7180, starting with the OS (Windows 10 Home 64-bit). I've got things almost the way I want them, so now I'd like to have access to my former hd files, and maybe transfer some of the Toshiba system files.
I have finally got my laptop and the external hd enclosure to show the available space of former hd (disk 1). "Disk 1 Unknown 465.76 GB Not Initialized" ("Disk 0 Basic 1863.02 GB Online"). Disk 1 does not show under "computer" and shows only as the enclosure's nomenclature. Both disk 0 and disk 1 are windows 10 os.
What steps do I take now to have access to the files/data on Disk 1 without erasing the files/data?

 

[The Paladin]

what ever you do, do not let windows "initialize your drive" that will wipe the data

 

[The Paladin]

try this
Open Start and typing CMD to open Command Prompt Window, right click on CMD and launch as Administrator
Type “chkdsk X:/f” (if the external hard drive is Drive X:replace accordingly), click Enter;
Now, it will start repairing damaged files, it will ask if you want to save lost chains into another location. Click "Yes".

 

[SkyNetRising]

You can't assign drive letter to uninitialized disk.

Obviously external drive enclosure is not handling drive the same way as, if it was connected directly to computer.
I'd connect both drives to a working desktop computer and copy important data.