On a Windows based operating system you can find out the serial number for a machine using WMIC – the command line interpreter for WMI. This can be used for the local machine or a remote machine.
From the command prompt:
For the local machine
wmic bios get serialnumber
For remote machine(s) using /node
wmic /node:[ADDRESS/COMPUTER NAME] bios get serialnumber
Computer names either comma delimited or listed within a file. File names have to be prefixed with &. Computer names/addresses within the file must be comma delimited or on separate lines.