How to Fix PowerShell GUI Freezes when Running

In some cases, when running a GUI PowerShell script, Winform is frozen then you cannot move your mouse and click on the form buttons again. 

The PowerShell is generally going to be single-threaded, so anything your script does will freeze the GUI. You can try the below code snippets to see how it works.

# Load the .Net assemblies
    Add-Type -AssemblyName System.Windows.Forms, System.Drawing
    [System.Windows.Forms.Application]::EnableVisualStyles()

# Create the form
    $form           = New-Object Windows.Forms.Form
    $form.Text      = 'www.bonguides.com'
    $form.Size      = New-Object System.Drawing.Size(650,400)

    $label          = New-Object System.Windows.Forms.Label
    $label.Location = New-Object System.Drawing.Point(20,10)
    $label.Size     = New-Object System.Drawing.Size(280,20)
    $label.Text     = 'Please select a DNS server:'

# Create a listbox control
    $listbox           = New-Object System.Windows.Forms.ListBox
    $listbox.Location  = New-Object System.Drawing.Point(20,30)
    $listbox.Size      = New-Object System.Drawing.Size(600,50)

# Add the items in the listbox
    @('1.1.1.1') | ForEach-Object {$listbox.Items.Add($_)}  

# Create button control
    $submitButton                   = New-Object System.Windows.Forms.Button
    $submitButton.BackColor         = "Green"
    $submitButton.Text              = "Submit"
    $submitButton.Size              = New-Object System.Drawing.Point (70,30)
    $submitButton.Location          = New-Object System.Drawing.Point(20,100)
    $submitButton.ForeColor         = "#ffffff"

# Create a textbox to display the output
    $textboxOutput                      = New-Object system.Windows.Forms.TextBox
    $textboxOutput.Multiline            = $true
    $textboxOutput.Text                 = "Waiting for results..."
    $textboxOutput.Size                 = New-Object System.Drawing.Size(600,200)
    $textboxOutput.Location             = New-Object System.Drawing.Point(20,140)
    $textboxOutput.BackColor            = "#1F1F1F"
    $textboxOutput.ForeColor            = 'Cyan'

# Event handler when click the button
    function DNSCheck {
        $textboxOutput.Text = (Test-Connection 1.1.1.1 -Count 6 | Out-String)
    }
    $submitButton.add_click({DNSCheck})

# Add the controls to the form then display the dialog.
    $form.controls.AddRange(@($listbox,$label,$submitButton,$textboxOutput))
    [void]$form.ShowDialog()

# Load the .Net assemblies
    Add-Type -AssemblyName System.Windows.Forms, System.Drawing
    [System.Windows.Forms.Application]::EnableVisualStyles()

# Create the form
    $form           = New-Object Windows.Forms.Form
    $form.Text      = 'www.bonguides.com'
    $form.Size      = New-Object System.Drawing.Size(650,400)

    $label          = New-Object System.Windows.Forms.Label
    $label.Location = New-Object System.Drawing.Point(20,10)
    $label.Size     = New-Object System.Drawing.Size(280,20)
    $label.Text     = 'Please select a DNS server:'

# Create a listbox control
    $listbox           = New-Object System.Windows.Forms.ListBox
    $listbox.Location  = New-Object System.Drawing.Point(20,30)
    $listbox.Size      = New-Object System.Drawing.Size(600,50)

# Add the items in the listbox
    @('1.1.1.1') | ForEach-Object {$listbox.Items.Add($_)}  

# Create button control
    $submitButton               = New-Object System.Windows.Forms.Button
    $submitButton.BackColor     = "Green"
    $submitButton.Text          = "Submit"
    $submitButton.Size          = New-Object System.Drawing.Point (70,30)
    $submitButton.Location      = New-Object System.Drawing.Point(20,100)
    $submitButton.ForeColor     = "#ffffff"

# Create a textbox to display the output
    $textboxOutput              = New-Object system.Windows.Forms.TextBox
    $textboxOutput.Multiline    = $true
    $textboxOutput.Text         = "Waiting for results..."
    $textboxOutput.Size         = New-Object System.Drawing.Size(600,200)
    $textboxOutput.Location     = New-Object System.Drawing.Point(20,140)
    $textboxOutput.BackColor    = "#1F1F1F"
    $textboxOutput.ForeColor    = 'Cyan'

# Event handler when click the button
    function DNSCheck {
        $job = Start-Job -ScriptBlock {
            $global:Result = Test-Connection 1.1.1.1 -Count 6 | Out-String
        }
        do { [System.Windows.Forms.Application]::DoEvents() } until ($job.State -eq "Completed")
        $textboxOutput.Text = $Global:Result
    }
    $submitButton.add_click({DNSCheck})

# Add the controls to the form then display the dialog.
    $form.controls.AddRange(@($listbox,$label,$submitButton,$textboxOutput))
    [void]$form.ShowDialog()

# Event handler when click the button
    function DNSCheck {
        $textboxOutput.Text = (Test-Connection 1.1.1.1 -Count 6 | Out-String)
    }
    $submitButton.add_click({DNSCheck})

# Event handler when click the button with DoEvents
    function DNSCheck {
        $job = Start-Job -ScriptBlock {
            $global:Result = Test-Connection 1.1.1.1 -Count 6 | Out-String
        }
        do { [System.Windows.Forms.Application]::DoEvents() } until ($job.State -eq "Completed")
        $textboxOutput.Text = $Global:Result
    }
    $submitButton.add_click({DNSCheck})