Download file using powershell commandlet

Command is working fine with windows server 2012 (powershell 4.0) is not working with windows 8 (powershell 4.0) for same.

I want to download file from iis-server.

 (New-Object System.Net.WebClient).DownloadFile('http://server12/vdir/v.exe','C:\pqr.exe')

I tried this. It worked fine for me in server 2012, but in windows 8 it gave me method invocation error

Exception calling "DownloadFile" with "2" argument(s): "An exception occurred during a WebClient request.