Running Powershell as an Administrator

From Powershell:

Start a new Powershell process as an Administrator from an existing Powershell command:

Start-Process powershell -Verb runAs

Or with arguments:

Start-Process powershell -Verb runAs -ArgumentList <Arguments>

From the command line:

Run the following from a non-powershell command line:

powershell -Command "Start-Process PowerShell –Verb RunAs"

Sources: