Is there no way to upgrade PowerShell to v5 or even v4?
On a fully patched Windows Server 2008 SP2, I've upgraded Powershell 2 to 3.
In order to install PowerShell 4+, you must install Windows Management Framework 4.0, and neither Windows Management Framework 4.0 or Windows Management Framework 5.1 supports Windows Server 2008 SP2
Source: WMF 5.1 Operating System Compatibility
WMF 4.0 can only be installed on the following operating systems.
As for PowerShell Core, since it includes
Microsoft.PowerShell.Management, it also wouldn't support Windows Server 2008 SP2
PowerShell Core (aka PowerShell 6) is officially supported on the following platforms:
- Windows Server 2008 R2, 2012 R2, 2016
Source: PowerShell Core 6.0