To get FQDN of local computer:
[System.Net.Dns]::GetHostByName($env:computerName)
or
[System.Net.Dns]::GetHostByName($env:computerName).HostName
To get FQDN of Remote computer:
[System.Net.Dns]::GetHostByName('mytestpc1')
or
For better formatted value use:
[System.Net.Dns]::GetHostByName('mytestpc1').HostName
- For remote machines make sure host is reachable.