There is no equivalent to the Unix watch command on Windows, but you can get close enough behavior.

Watching commands with PowerShell
# Similar to `watch <command>`
PS> while ($true) {<your command>; sleep -Seconds 2}

PS> while ($true) {(Get-Service -Name 'Remote Desktop Services').Status; sleep -Seconds 2}

You can also follow log file output similar to the Unix tail command.

Tailing logs with PowerShell:
# Similar to `tail --follow <filename>`
PS> Get-Content -Path <logfile> -Tail 10 –Wait

PS> Get-Content -Path 'C:\app.log' -Tail 10 –Wait