If you are looking to find BIOS serial number from CMD, then
wmic bios is the command you would need. Below is the exact command you can run on any Windows computer to retrieve serial number.
wmic bios get serialnumber
C:\>wmic bios get serialnumber SerialNumber BP69SDK
We can find other bios information also using ‘wmic bios get’ command. In the above command you need to replace ‘serialnumber‘ with the appropriate property of bios. Use the below command to get the list of properties.
wmic bios get /?