Block user input. Mouse, and keyboard are disabled for the duration.

BlockUserInput.ps1

$code = @"
    [DllImport("user32.dll")]
    public static extern bool BlockInput(bool fBlockIt);
"@

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

Function Disable-UserInput {
    param([int]$Seconds=5)
    $userInput::BlockInput($true) | out-null
    Start-Sleep $seconds
    $userInput::BlockInput($false) | out-null
}

Disable-UserInput