Windows PowerShell is a command shell and scripting language for automating administration on Windows. It can inspect processes and services, work with files and Registry data, and run the same administrative commands across multiple computers. Its commands exchange structured .NET objects, allowing a script to work with individual properties rather than extract values from a screenful of text.
Windows PowerShell uses the .NET Framework and is separate from the newer, cross-platform PowerShell product. It remains relevant to Windows administration and scripts built around that environment, although it no longer receives new features.
Object pipelines
A pipeline joins commands so that the output of one becomes input for the next. For example, a file listing can pass through a filter that keeps files matching a condition, a sorting command that orders them by length, and a table formatter that displays selected properties. The file objects retain their properties through the processing stages; formatting determines how the final result appears.
Windows PowerShell applies the same approach to system objects. A command can retrieve services and pass selected service objects to another command that changes their running state. The receiving command must support the kind of input being passed. Results can also go to CSV files, XML serialization, or text output, depending on whether the next task needs structured records or a readable report.
Registry, certificate and environment drives
Providers give several Windows data stores a drive-and-path interface. Alongside ordinary file paths, Windows PowerShell exposes Registry keys through drives such as HKLM: and HKCU:, certificates through Cert:, and environment variables through Env:. These paths represent their respective stores, rather than extra disk partitions.
Shared commands let a script inspect items, move through containers, and create or change supported data. Creating an item in a filesystem location can make a file or folder, while the corresponding operation in a Registry drive can create a key. Each provider determines the operations and additional parameters available for its data.
Reusable scripts
Commands can be saved in plain-text .ps1 files and combined with variables, functions, conditional branches, and loops. Parameters let the same script accept different computer names, paths, or other values without editing its commands each time.
Modules package related functions, commands, providers, and other resources for reuse in different sessions or scripts. Windows PowerShell can load an installed module when one of its commands is first used, or load it explicitly with Import-Module. Scripts can carry their own help text and digital signatures; the computer’s execution policy can affect which scripts are permitted to run.
Remote sessions
Windows PowerShell can send a command block or a local script to one or more remote computers and return their results. Invoke-Command handles this form of execution, while Enter-PSSession provides an interactive prompt for working on a single remote machine. PowerShell remoting must be configured on the participating computers.
A temporary connection ends when its command finishes. A persistent PSSession keeps variables and functions available between calls, so later commands can use data collected earlier in that session.
Windows PowerShell ISE
Windows PowerShell ISE combines a script editing pane with a console for commands and output. Syntax coloring, IntelliSense, and context-sensitive help assist with entering commands and their parameters. Selected lines can run independently, allowing a section of a script to be examined without executing the whole file.
Its debugger supports breakpoints and step-by-step execution to follow a script’s behavior. The editor highlights the part being executed and can open files containing called functions or scripts. ISE requires a graphical Windows environment and is unavailable on Server Core.
Desired State Configuration
Desired State Configuration lets administrators specify how a computer should be configured using resource blocks for subjects such as services, files, Registry values, and Windows features. A configuration identifies target computers and assigns the required settings to their resources. It produces configuration data that can then be applied to those targets.
Windows PowerShell can test whether a computer still matches its applied configuration. Reapplying that configuration brings affected resources back to the specified state, so the administrator can maintain the same definition as machines change over time.
