Before proceeding with the PowerShell upgrade, your server must have the following:

You can find the installer on the Official Microsoft Download Center .

To download and install PowerShell 5.0 (via Windows Management Framework 5.0) on Windows Server 2008 R2, you must first ensure your system meets specific prerequisites. Note that Microsoft officially recommends upgrading directly to (WMF 5.1), as it is the last supported version for this operating system and resolves several bugs found in the 5.0 release. Prerequisites for Installation

The installation package for PowerShell is bundled within the Windows Management Framework (WMF).

PowerShell 5.0/5.1 is only compatible with Windows Server 2008 R2 SP1 .

For Windows Server 2008 R2, select the 64-bit package, typically named Win7AndW2K8R2-KB3191566-x64.zip for WMF 5.1. Installation Steps Download Windows Management Framework 5.0 ... - Microsoft

While later versions of the WMF 5.1 installer removed this requirement, older WMF 5.0 documentation often noted WMF 4.0 as a recommended intermediate step to ensure stability. How to Download PowerShell 5.0/5.1