Windows PowerShell Integrated Scripting Environment (ISE) is a host application that enables you to write, run, and test scripts and modules in a graphical and intuitive environment.
It is shipped as feature with Windows Server 2008R2 and you can install it from Feature Role.
for that Open Server Manager >> Select Features Option >> Select Add Features
Click Next and Install
To open PowerShell ISE click on Start and type PowerShell ISE.