Step 1: Installing Latest Version (3.0) of Power Shell ISE
Go to Microsoft Download Center "http://www.microsoft.com/en-us/download/details.aspx?id=34595" and download Power Shell ISE 3.0 for windows 7. It is shipped with Windows 8 and Windows Server 2012 by default.
Step 2: Set Execution Policy
Then, you have to set execution policy to "Unrestricted" to run any script and to get intellisense during command writing in power shell.
Command: "Set-ExecutionPolicy -ExecutionPolicy Unrestricted"
Go to: https://technet.microsoft.com/en-us/library/hh847748.aspx for detailed explanation.
Now after performing above mentioned steps, you are ready to execute any power shell command using power shell ISE.