PowerShell try, catch and finally

Handle a failing operation explicitly and keep cleanup separate from success reporting.

Lesson 2 min read Windows PowerShell 5.1 and PowerShell 7

Written and tested by Dhrub Bharali · Updated 02 October 2026

Overview

The example divides by zero, producing a terminating error that enters catch. The line that would print Result is skipped. Finally then runs during normal error unwinding, making it a place for releasing resources.

Many cmdlets report non-terminating errors by default. When a particular failure must enter catch, put -ErrorAction Stop on that command. Avoid changing the behavior of unrelated operations accidentally through a broad preference setting.

Inside catch, $_ is the ErrorRecord for the caught error. Preserve the message, target and operation context in your log. If the caller must know the operation failed, rethrow or return an explicit failure record instead of printing an error and then reporting success.

Finally is useful for disposing a stream or removing a temporary session. It does not mean a script can recover from forced process termination, and cleanup must not hide the original error with an avoidable second failure.

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Read the command and its supplied arguments. This example requires real PowerShell or its module; this diagram does not execute it.

try {
  $result = 10 / 0
  Write-Output "Result: $result"
}
catch {
  Write-Output "Caught: $($_.Exception.Message)"
}
finally {
  Write-Output 'Finally always runs.'
}

Stage 1tryPositional values or no named parameters

What happens

Predict the two messages before inspecting the example: the caught error and the final cleanup message. In a real test, replace division by zero with a missing file read and compare behavior with and without -ErrorAction Stop.

Worth remembering

Decide which failures stop the operation, what the caller receives, and how resources are released.

Primary documentation

Microsoft Learn: try catch finally

Try it

Illustrative output · values vary by environment

1PS> try {

2PS> $result = 10 / 0

3PS> Write-Output "Result: $result"

4PS> }

5PS> catch {

6PS> Write-Output "Caught: $($_.Exception.Message)"

7PS> }

8PS> finally {

9PS> Write-Output 'Finally always runs.'

10PS> }

Example reader

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try {
  $result = 10 / 0
  Write-Output "Result: $result"
}
catch {
  Write-Output "Caught: $($_.Exception.Message)"
}
finally {
  Write-Output 'Finally always runs.'
}

Ready to inspect.

Catches a terminating error and shows that finally runs either way.

Show reference output

Illustrative output · values vary by environment

Caught: Attempted to divide by zero.
Finally always runs.

Practise this

Choose a task

Catch a missing service

Request MissingService with -ErrorAction Stop inside try/catch. Return Service unavailable from the catch block.

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