If you don't find your new disk on the file explorer, then it need to be initialised. Initialising the disk requires that the disk should not be formatted before.
Steps to initialise a new disk on Windows
To make disk ready for Windows use, initialise it by following general steps:
Right-click the disk > tap 'Initialize Disk'.
To continue with default style, click 'ok'.
Right-click unallocated space then tap 'New Simple Volume'.
Tap 'Next', confirm volume size.
Tap 'Next', follow on-screen prompts.
Lastly, tap 'Finish'.
Note:
Be cautious that chosen disk is selected in the Initialize Disk dialog box.