Windows Central demonstrates how to quickly troubleshoot and resolve this issue on Windows 10 if the hard drive is missing in File Explorer using tools like Disk Management, Device Manager, DiskPart, and others.

How to fix hard drive not showing in Windows 10 File Explorer

If the secondary hard drive isn't showing up in File Explorer, you can use these steps to resolve the issue on Windows 10.

How to fix hard drive not showing in Windows 10 File Explorer