Run a PowerShell script

There are several ways to run a PowerShell script.

Before running any scripts on a new PowerShell installation, you must first set an appropriate Execution Policy,
e.g. Set-ExecutionPolicy RemoteSigned

If the script has been downloaded from the internet and saved as a file then you may also need to right click on the script, select properties, then unblock. If you just copy and paste the text of the script, this is not needed.

A PowerShell script is the equivalent of a Windows CMD or MS-DOS batch file, the file should be saved as plain ASCII text with a .ps1 extension, e.g. MyScript.ps1

Call or Invoke a script to run it

The most common (default) way to run a script is by calling it:

PS C:\> & "C:\Batch\My first Script.ps1"

PS C:\> & cscript /nologo "C:\Batch\another.vbs"

If the path does not contain any spaces, then you can omit the quotes and the '&' operator

PS C:\> C:\Batch\Myscript.ps1

If the script is in the current directory, you can omit the path but must instead explicitly indicate the current directory using .\ (or ./ will also work)

PS C:\> .\Myscript.ps1

An important caveat to the above is that the currently running script might not be located in the current directory.

Call one PowerShell script from another script saved in the same directory:

#Requires -Version 3.0
& "$PSScriptRoot\set-consolesize.ps1" -height 25 -width 90

When you invoke a script using the syntax above, variables and functions defined in the script will disappear when the script ends.¹

An alternative which allows running a script (or command) on local or remote computers is Invoke-Command

PS C:\> invoke-command -filepath c:\scripts\test.ps1 -computerName Server64

¹unless they are explicitly defined as globals: Function SCOPE:GLOBAL or Filter SCOPE:GLOBAL or Set-Variable -scope "Global"

Run a PowerShell Script from the GUI or with a shortcut

This can be done by running PowerShell.exe with parameters to launch the desired script.

Run As Administrator (Elevated)

See the PowerShell elevation page for ways of running a script or a PowerShell session "As admin"

Dot Sourcing

When you dot source a script, all variables and functions defined in the script will persist even when the script ends.

Run a script by dot-sourcing it:

PS C:\> . "C:\Batch\My first Script.ps1"

Dot-sourcing a script in the current directory:

PS C:\> . .\Myscript.ps1"

Run a CMD batch file

Run a batch script from PowerShell:
PS C:\> ./demo.cmd

Early versions of PowerShell would only run internal CMD commands if the batch file was run by explicitly calling the CMD.exe shell and passing the batch file name.

Run a single CMD internal command

This will run the CMD.exe version of DIR rather than the powershell DIR alias for Get-ChildItem:

PS C:\> CMD.exe /C dir

Run a VBScript file

Run a vb script from PowerShell:
PS C:\> cscript c:\batch\demo.vbs

The System Path

If you run a script (or even just enter a command) without specifying the fully qualified path name, PowerShell will search for it as follows:

Currently defined aliases

Currently defined functions

Commands located in the system path.

#Yeah, I'm gonna run to you, cause when the feelin's right I'm gonna stay all night, I'm gonna run to you# ~ Bryan Adams

Related PowerShell Cmdlets:

#requires - Prevent a script from running without a required element.
Invoke-Command - Run commands on local and remote computers.
Invoke-Expression - Run a PowerShell expression.
Invoke-Item - Invoke an executable or open a file (START).
The call operator (&) - Execute a command, script or function.
Set-Variable - Set a variable and its value.
Functions - Write a named block of code.
CMD Shell: Run a script from the CMD shell
VBScript: Run a script from VBScript