How to find Serial number of machine?

To find out the serial number of the machine, go to windows command prompt and type following command on the command prompt,

1. Start > cmd
2. C:\Users\XYZ > wmic csproduct get identifyingnumber,vendor,name

It will give you the output like
IdentifyingNumber    Name          Vendor
L3ZZ896                  5897X7Y     LENOVO

Where IdentifyingNumber is Serial number of machine, Name is Productid and Vendor is the name of manufacturer