When you use the Get-Credential cmdlet, you get a GUI dialog box to enter the credentials. This is the "Common Criteria Certified" way of handling credentials. It is also a pain in the butt at times. If you are an admin, you can alter this and request credentials via the command line as follows:

PS> $key = "HKLM:\\SOFTWARE\\Microsoft\\PowerShell\\1\\ShellIds" PS> Set-ItemProperty $key ConsolePrompting True PS> Get-Credential

cmdlet Get-Credential at command pipeline position 1 Supply values for the following parameters: Credential User: ntdev\\jsnover Password for user ntdev\\jsnover: **************

UserName Password

ntdev\\jsnover System.Security.SecureString

[http://blogs.msdn.com/powershell/archive/2008/06/20/ getting-credentials-from-the-command-line.aspx]