There may be a reason you need to find the serial number of your hard drive.
Assuming you cannot read the number on the hard disk itself you can query this using the command line and using powershell
In this article we look at both of these options
Command line option
Click Win+X, and tap on Command Prompt
Copy and paste the command below into the command prompt, and press Enter.
wmic diskdrive get model,name,serialnumber
You will now see the model, name, and serial number listed for your hard drives. Like the following

cmd hard disks
Powershell option
Press the Win + S keys to open the Search.
Type powershell into the search box, and click on Windows PowerShell in the search results at the top.

cmd hard disks
Powershell will open
Copy and paste the command below into PowerShell, and press Enter.
Get-WMIObject win32_physicalmedia | Format-List Tag,SerialNumber
You will now see the tag and serial number listed for the hard drives in your PC. Like the following

powershell hard disks