To find serial number of a given system ,you need system host-name of targeted machine , and it has to be online in the lan (network)

then open “cmd” then ping your hostname¬†

if you receive all 4 packets back that means your targeted machine is online in the lan

now type following command in the command prompt

wmic /NODE: "INDIA-L090" bios get serialnumber

In this tutorial i have used “INDIA-L090” as host name this may vary in your case