Installing and Upgrading PowerShell 7 on Windows

TLDR

• Windows PowerShell (5.1) and PowerShell 7 are completely different products; both can coexist on the same system.
• PowerShell 7 uses UTF-8 (without BOM) encoding, which effectively resolves character encoding issues when interacting with Chinese characters and Git in older versions.
• Installation is recommended when you need cross-platform scripts, use AI-generated scripts, or when tools explicitly require PowerShell 6+.
• After installing PowerShell 7, you must run the Update-Help command to obtain the complete offline documentation.
• Use WinGet for quick installation and version upgrades.

Differences between Windows PowerShell and PowerShell 7

When you might encounter this: When you find that the built-in PowerShell cannot run modern tools (such as Copilot CLI) or displays garbled text when handling Chinese characters.

• Underlying Architecture: Windows PowerShell is based on the closed-source .NET Framework and is limited to Windows; PowerShell 7 is based on open-source .NET and supports cross-platform execution.
• Lifecycle: Windows PowerShell has ceased new feature development and only receives maintenance updates.
• Default Encoding: PowerShell 7 uses UTF-8 (without BOM) by default, solving the garbled text issues encountered in older versions when handling plain text files and Chinese characters.
• Executable Isolation: Both can coexist; the Windows PowerShell executable is powershell.exe, while PowerShell 7 is pwsh.exe.

Installation Guide

When you might encounter this: When you need to install or upgrade PowerShell 7 to meet development environment requirements.

WinGet automatically configures environment variables after installation, so no manual configuration is required.

• Search for available versions:

  winget search --id Microsoft.PowerShell

• Install the latest stable version:

  winget install --id Microsoft.PowerShell --source winget

• Upgrade to the latest version with one click:

  winget upgrade --id Microsoft.PowerShell

• Uninstall:

  winget uninstall --id Microsoft.PowerShell

Get-Help Documentation Mechanism

When you might encounter this: When you run Get-Help but find that you cannot view examples or detailed parameter descriptions; this is because PowerShell does not bundle offline documentation by default.

If you need complete example documentation, you can use the following methods:

• Online Query: Use the -Online parameter (e.g., Get-Help Get-Process -Online) to open the official web-based documentation directly in your browser.
• Download Offline Files: Run the following command as an administrator:

  Update-Help -UICulture zh-tw, en-US -Force -ErrorAction SilentlyContinue

Parameter Explanation

• -UICulture zh-tw, en-US: Specifies the download language, adding en-US as a fallback.
• -Force: Forces a re-download of the help files.
• -ErrorAction SilentlyContinue: Ignores error messages generated by modules that do not provide online help files.

When is an additional installation of the new version required?

When you might encounter this: When you are hesitant about whether to remove the old version or install the new one.

• AI Script Baseline: AI-generated scripts are mostly based on PowerShell 6+, and they often fail when executed in older versions.
• Encoding Issues: Resolves the issue where Windows PowerShell 5.1 misidentifies UTF-8 without BOM files as ANSI.
• Tool Compatibility: Modern development tools like Copilot CLI explicitly require PowerShell 6+.
• Cross-Platform Requirements: If you need to write scripts that are compatible with Windows, Linux, and macOS.

TIP

Both can coexist; there is no need to remove Windows PowerShell.

Change Log

• 2026-03-25 Initial documentation created.