Open the command prompt (Start – > CMD) and type the following command:
wmic bios get serialnumber
Another command that will also print the model number (or make) of your computer is:
wmic csproduct get name, identifyingnumber
The system model number can also be found using the System Information program available under All Programs – > Accessories – > System Tools.
The above commands should work on Windows 7, XP and Windows XP Pro machine as wmic.exe didn’t ship with the previous editions of Windows.