Blocking User Input

by Apr 3, 2019

If a PowerShell script needs to perform critical steps, and user interaction must be prohibited, you can use API calls to temporarily disable all keyboard input. Locking keyboard input does require Administrator privileges.

Here is a script illustrating how to block all keyboard input for 4 seconds:

#requires -RunAsAdministrator
# when run without administrator privileges, the keyboard will not be blocked!

# get access to API functions that block user input
# blocking of keyboard input requires administrator privileges
$code = @'
    public static extern bool BlockInput(bool fBlockIt);

$userInput = Add-Type -MemberDefinition $code -Name Blocker -Namespace UserInput -PassThru

# block user input
$null = $userInput::BlockInput($true)

Write-Warning "Your input has been disabled for 4 seconds..."
Start-Sleep -Seconds 4

# unblock user input
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