I looked at that on my system and I don’t have a ‘windowsversion’ property on the returned object. I think you want to look at ‘buildnumber’ or ‘version’.
Get-WmiObject -class win32_operatingsystem -ComputerName PC1 | Select-Object version
I’ve actually created function a while back to get this information using the registry (as @ArtisanByteCrafter suggested) from multiple remote servers.