PS Skript Client reboot mit Useroption

Add-Type -AssemblyName System.Windows.Forms
[System.Windows.Forms.Application]::EnableVisualStyles()
Add-Type -Assembly System.Drawing 
$Form = New-Object system.Windows.Forms.Form

[int32]$height = 100
[int32]$width = 300
$Form.ClientSize = "$width,$height"  
$Form.text = "Neustart"  
$Form.TopMost = $true
$CenterScreen = [System.Windows.Forms.FormStartPosition]::CenterScreen;
$Form.StartPosition = $CenterScreen
$global:timeToAdd = 0

$label = New-Object system.Windows.Forms.Label
$label.width = 1000
$label.height = 40
$label.text = "Der PC muss neu gestartet werden.`nWann soll der Neustart durchgeführt werden?"  
$label.location = New-Object System.Drawing.Point(0, 10)

$button = New-Object system.Windows.Forms.Button
$button.width = 100   
$button.height = 30
$button.text = "In 30 Minuten"  
$button.location = New-Object System.Drawing.Point(0, 50)
$button.Font = 'Microsoft Sans Serif,10'  
$button.Add_Click({
        $global:timeToAdd = 30
        $form.Close()
    })

$button2 = New-Object system.Windows.Forms.Button
$button2.width = 100   
$button2.height = 30
$button2.text = "In 60 Minuten"  
$button2.location = New-Object System.Drawing.Point(100, 50)
$button2.Font = 'Microsoft Sans Serif,10'  
$button2.Add_Click({
        $global:timeToAdd = 60
        $form.Close()
    })

$button3 = New-Object system.Windows.Forms.Button
$button3.width = 100   
$button3.height = 30
$button3.text = "Sofort"  
$button3.location = New-Object System.Drawing.Point(200, 50)
$button3.Font = 'Microsoft Sans Serif,10'  
$button3.Add_Click({
        Restart-Computer -Force
        $form.Close()
    })

$Form.controls.Add($button)
$Form.controls.Add($button2)
$Form.controls.Add($button3)
$Form.Controls.Add($label)

[void]$Form.ShowDialog()

$action = New-ScheduledTaskAction -Execute 'powershell.exe' -Argument '-Command "Restart-Computer -Force"'  
$principal = New-ScheduledTaskPrincipal -UserID "NT AUTHORITY\SYSTEM" -LogonType ServiceAccount -RunLevel Highest  
$trigger = New-ScheduledTaskTrigger -At (Get-Date).AddMinutes($global:timeToAdd) -Once

Register-ScheduledTask -Action $action -TaskName 'Restart' -TaskPath '\' -Principal $principal -Trigger $trigger  

$Form.FormBorderStyle = 0