In which version of Windows is PowerShell installed by default?
Windows 7/Server 2008 R2 are the first Windows versions to come with PowerShell installed, by default.
Windows PowerShell 2.0 needs to be installed on Windows Server 2008 and Windows Vista only. It is already installed on Windows Server 2008 R2 and Windows 7.
Ignoring the horribleness of installing XP SP2 in this day and age, if not having PowerShell installed by default is a problem, you have many options to correct that, both retroactively (like GPOs or startup/logon scripts to install it) and going forward (by slipstreaming it into an ISO image or a machine that you deploy).
Short answer
As already given: Windows XP doesn't come with PowerShell integrated, so your specific solution is to install PS1 on WinXP SP2 assuming the availability of the software.
Long answer
Reading the dedicated section PowerShell #Version on Wikipedia gave me the following information. I stripped details and most of the (reliable and informative) for this overview:
Windows PowerShell Versions
| Version | integrated with | released for |
|---|---|---|
| 1.0 | Windows XP SP2 Server 2003 SP1 Windows Vista |
|
| 2.0 | Windows 7 Windows Server 2008 R2[59] |
Windows XP SP3 Windows Server 2003 SP2 Windows Vista SP1 |
| 3.0 | Windows 8 Windows Server 2012 |
Windows 7 SP1 Windows Server 2008 SP1 Windows Server 2008 R2 SP1 |
| 4.0 | Windows 8.1 Windows Server 2012 R2 |
Windows 7 SP1 Windows Server 2008 R2 SP1 Windows Server 2012 |
| 5.1 | Windows 10 Anniversary Update Windows Server 2016 |
Windows 7 Windows Server 2008 Windows Server 2008 R2 Windows Server 2012 Windows Server 2012 R2 |
PowerShell Core 6
PowerShell Core 6 is the first free, cross-plattform implementation of PoweShell (Note the missing Windows and the additional Core in the name)
- PowerShell is Microsoft’s latest open source release, coming to Linux, OS X | Ars Technica
- PowerShell Core 6.0: Generally Available (GA) and Supported! | PowerShell Team
PowerShell 7
PowerShell 7 replaces PowerShell Core 6.x products and Windows PowerShell 5.1 with focus on becoming a viable replacement for PS 5.1. The Core part in the name was removed to reflect the join.
- PowerShell 7 Roadmap | PowerShell Team
PowerShell is not installed with Windows XP. You have to manually install it afterwards.