Get-Wmiobject not working

hey guys im sorry for being such a noob on this but im stuck in this very first question,
What is the Build Number of the target workstation?

I’ve tried to run this on cmd after i RDP into the system.\

Get-WmiObject -Class win32_OperatingSystem | select Version,BuildNumber

It keeps on saying the the "Get-WmiObject is not recogniz. what do i have to do?

Has you enter the Power shell? This error message locks like a cmd shell error message. You can try to start the Powershell.exe first.

Refer to the WMI Permissions and General Errors topic on the AskPerf Support Center for testing and ensuring that WMI is working locally on each box as well as data collection before moving to troubleshooting remote connectivity. Click Start, click Run, type wmimgmt.msc, and then click OK.

Regards,
Rachel Gomez