So I needed to run a PowerShell script on Windows Server 2008 R2, and needed PowerShell ISE.
I realised the server I was on did not have it installed.
As you can see here when doing a quick search, there is no PowerShell ISE option available.
Here is how you install PowerShell ISE;
Open Server Manager > Select Features > Add Features
Once selected, scroll down and find PowerShell Integrated Scripting Environment (ISE)
Once selected, select Next and hit Install
Once installed do a quick browse for PowerShell ISE, you should see it in the list now (below)
Hope this helps!