Hey there, let's tackle your problem step by step. First, a key thing to understand: the popup generated by $Host.UI.PromptForChoice() is managed directly by your PowerShell host environment (like the Windows PowerShell console or ISE) — it's not a standard WinForms/WPF window. That's why your attempts to use $Host.Location, .TopMost, or modify FormBorderStyle aren't working: those properties affect the PowerShell host window itself, not this confirmation popup. Plus, the popup's border style is hard-coded into the host, so you can't tweak it via native PowerShell APIs.

Here are practical solutions to get the behavior you want:

Solution 1: Use WinForms MessageBox for Full Control #

If you need to set the popup's exact position, keep it on top, or adjust styling, switching to a WinForms-based dialog is your best bet. You can even "anchor" it to a specific screen position using a hidden helper form:

# Load the WinForms assembly
Add-Type -AssemblyName System.Windows.Forms

# Create a hidden helper form to define the popup's position
$positioningForm = New-Object System.Windows.Forms.Form
$positioningForm.StartPosition = [System.Windows.Forms.FormStartPosition]::Manual
$positioningForm.Location = [System.Drawing.Point]::new(0, 0) # Set your desired (X,Y) here
$positioningForm.ShowInTaskbar = $false
$positioningForm.Visible = $false

# Show the confirmation dialog, using the hidden form to control its position
$userChoice = [System.Windows.Forms.MessageBox]::Show(
    $positioningForm,
    'Are you sure you want to proceed?',
    'Admin Confirmation',
    [System.Windows.Forms.MessageBoxButtons]::YesNo,
    [System.Windows.Forms.MessageBoxIcon]::Question
)

# Handle the user's selection
switch ($userChoice) {
    'Yes' { Write-Host 'Proceeding with the action...' }
    'No' { Write-Host 'Action cancelled.' }
}

# Clean up the helper form
$positioningForm.Dispose()

This method lets you place the popup exactly where you want, and you can customize its appearance further by building a fully custom WinForms Form if you need even more control (like removing borders entirely).

Solution 2: Fix the "Popup Behind Form" Issue Quickly #

If you just need the confirmation popup to show up in front of your existing form (instead of adjusting its exact position), you can temporarily disable your form's "topmost" status before calling PromptForChoice:

# Assume your existing form is stored in $customForm
$customForm.TopMost = $false

# Run your original PromptForChoice code
$title = 'Admin Confirmation'
$question = 'Are you sure you want to proceed?'
$choices = New-Object Collections.ObjectModel.Collection[Management.Automation.Host.ChoiceDescription]
$choices.Add((New-Object Management.Automation.Host.ChoiceDescription -ArgumentList '&Yes'))
$choices.Add((New-Object Management.Automation.Host.ChoiceDescription -ArgumentList '&No'))
$decision = $Host.UI.PromptForChoice($title, $question, $choices, 1)

# Restore your form's topmost status
$customForm.TopMost = $true

# Process the decision
if ($decision -eq 0) {
    Write-Host 'User selected Yes'
} else {
    Write-Host 'User selected No'
}

Your Backup Plan: Side-by-Side Forms #

If neither of the above works for your use case, going with two side-by-side forms is a valid fallback. Just make sure to:

• Set both forms' StartPosition to Manual
• Define unique Location values for each to position them side by side
• Use the Form.Owner property to link the forms if you need to manage their window hierarchy

内容的提问来源于stack exchange，提问作者Josh C