How to: Configure the ClickOnce trust prompt behavior

You can configure the ClickOnce trust prompt to control whether end users are given the option of installing ClickOnce applications, such as Windows Forms applications, Windows Presentation Foundation applications, console applications, WPF browser applications, and Office solutions. You configure the trust prompt by setting registry keys on each end user's computer.

The following table shows the configuration options that can be applied to each of the five zones (Internet, UntrustedSites, MyComputer, LocalIntranet, and TrustedSites).

Option Registry setting value Description
Enable the trust prompt. Enabled The ClickOnce trust prompt is display so that end users can grant trust to ClickOnce applications.
Restrict the trust prompt. AuthenticodeRequired The ClickOnce trust prompt is only displayed if ClickOnce applications are signed with a certificate that identifies the publisher.
Disable the trust prompt. Disabled The ClickOnce trust prompt is not displayed for any ClickOnce applications that are not signed with an explicitly trusted certificate.

The following table shows the default behavior for each zone. The Applications column refers to Windows Forms applications, Windows Presentation Foundation applications, WPF browser applications, and console applications.

Zone Applications Office solutions
MyComputer Enabled Enabled
LocalIntranet Enabled Enabled
TrustedSites Enabled Enabled
Internet Enabled AuthenticodeRequired
UntrustedSites Disabled Disabled

You can override these settings by enabling, restricting, or disabling the ClickOnce trust prompt.

Enable the ClickOnce trust prompt

Enable the trust prompt for a zone when you want end users to be presented with the option of installing and running any ClickOnce application that comes from that zone.

To enable the ClickOnce trust prompt by using the registry editor

  1. Open the registry editor:

    1. Click Start, and then click Run.

    2. In the Open box, type regedit, and then click OK.

  2. Find the following registry key:

    \HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\.NETFramework\Security\TrustManager\PromptingLevel

    If the key does not exist, create it.

  3. Add the following subkeys as String Value, if they do not already exist, with the associated values shown in the following table.

    String Value subkey Value
    Internet Enabled
    UntrustedSites Disabled
    MyComputer Enabled
    LocalIntranet Enabled
    TrustedSites Enabled

    For Office solutions, Internet has the default value AuthenticodeRequired and UntrustedSites has the value Disabled. For all others, Internet has the default value Enabled.

To enable the ClickOnce trust prompt programmatically

  1. Create a Visual Basic or Visual C# console application in Visual Studio.

  2. Open the Program.vb or Program.cs file for editing and add the following code.

    Dim key As Microsoft.Win32.RegistryKey  
    key = Microsoft.Win32.Registry.LocalMachine.CreateSubKey("SOFTWARE\MICROSOFT\.NETFramework\Security\TrustManager\PromptingLevel")  
    key.SetValue("MyComputer", "Enabled")  
    key.SetValue("LocalIntranet", "Enabled")  
    key.SetValue("Internet", "Enabled")  
    key.SetValue("TrustedSites", "Enabled")  
    key.SetValue("UntrustedSites", "Disabled")  
    key.Close()  
    
    Microsoft.Win32.RegistryKey key;  
    key = Microsoft.Win32.Registry.LocalMachine.CreateSubKey("SOFTWARE\\MICROSOFT\\.NETFramework\\Security\\TrustManager\\PromptingLevel");  
    key.SetValue("MyComputer", "Enabled");  
    key.SetValue("LocalIntranet", "Enabled");  
    key.SetValue("Internet", "AuthenticodeRequired");  
    key.SetValue("TrustedSites", "Enabled");  
    key.SetValue("UntrustedSites", "Disabled");  
    key.Close();  
    
  3. Build and run the application.

Restrict the ClickOnce trust prompt

Restrict the trust prompt so that solutions must be signed with Authenticode certificates that have known identity before users are prompted for a trust decision.

To restrict the ClickOnce trust prompt by using the registry editor

  1. Open the registry editor:

    1. Click Start, and then click Run.

    2. In the Open box, type regedit, and then click OK.

  2. Find the following registry key:

    \HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\.NETFramework\Security\TrustManager\PromptingLevel

    If the key does not exist, create it.

  3. Add the following subkeys as String Value, if they do not already exist, with the associated values shown in the following table.

    String Value subkey Value
    UntrustedSites Disabled
    Internet AuthenticodeRequired
    MyComputer AuthenticodeRequired
    LocalIntranet AuthenticodeRequired
    TrustedSites AuthenticodeRequired

To restrict the ClickOnce trust prompt programmatically

  1. Create a Visual Basic or Visual C# console application in Visual Studio.

  2. Open the Program.vb or Program.cs file for editing and add the following code.

    Dim key As Microsoft.Win32.RegistryKey  
    key = Microsoft.Win32.Registry.LocalMachine.CreateSubKey("SOFTWARE\MICROSOFT\.NETFramework\Security\TrustManager\PromptingLevel")  
    key.SetValue("MyComputer", "AuthenticodeRequired")  
    key.SetValue("LocalIntranet", "AuthenticodeRequired")  
    key.SetValue("Internet", "AuthenticodeRequired")  
    key.SetValue("TrustedSites", "AuthenticodeRequired")  
    key.SetValue("UntrustedSites", "Disabled")  
    key.Close()  
    
    Microsoft.Win32.RegistryKey key;  
    key = Microsoft.Win32.Registry.LocalMachine.CreateSubKey("SOFTWARE\\MICROSOFT\\.NETFramework\\Security\\TrustManager\\PromptingLevel");  
    key.SetValue("MyComputer", "AuthenticodeRequired");  
    key.SetValue("LocalIntranet", "AuthenticodeRequired");  
    key.SetValue("Internet", "AuthenticodeRequired");  
    key.SetValue("TrustedSites", "AuthenticodeRequired");  
    key.SetValue("UntrustedSites", "Disabled");  
    key.Close();  
    
  3. Build and run the application.

Disable the ClickOnce trust prompt

You can disable the trust prompt so that end users are not given the option to install solutions that are not already trusted in their security policy.

To disable the ClickOnce trust prompt by using the registry editor

  1. Open the registry editor:

    1. Click Start, and then click Run.

    2. In the Open box, type regedit, and then click OK.

  2. Find the following registry key:

    \HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\.NETFramework\Security\TrustManager\PromptingLevel

    If the key does not exist, create it.

  3. Add the following subkeys as String Value, if they do not already exist, with the associated values shown in the following table.

    String Value subkey Value
    UntrustedSites Disabled
    Internet Disabled
    MyComputer Disabled
    LocalIntranet Disabled
    TrustedSites Disabled

To disable the ClickOnce trust prompt programmatically

  1. Create a Visual Basic or Visual C# console application in Visual Studio.

  2. Open the Program.vb or Program.cs file for editing and add the following code.

    Dim key As Microsoft.Win32.RegistryKey  
    key = Microsoft.Win32.Registry.LocalMachine.CreateSubKey("SOFTWARE\MICROSOFT\.NETFramework\Security\TrustManager\PromptingLevel")  
    key.SetValue("MyComputer", "Disabled")  
    key.SetValue("LocalIntranet", "Disabled")  
    key.SetValue("Internet", "Disabled")  
    key.SetValue("TrustedSites", "Disabled")  
    key.SetValue("UntrustedSites", "Disabled")  
    key.Close()  
    
    Microsoft.Win32.RegistryKey key;  
    key = Microsoft.Win32.Registry.LocalMachine.CreateSubKey("SOFTWARE\\MICROSOFT\\.NETFramework\\Security\\TrustManager\\PromptingLevel");  
    key.SetValue("MyComputer", "Disabled");  
    key.SetValue("LocalIntranet", "Disabled");  
    key.SetValue("Internet", "Disabled");  
    key.SetValue("TrustedSites", "Disabled");  
    key.SetValue("UntrustedSites", "Disabled");  
    key.Close();  
    
    
  3. Build and run the application.

See also

Secure ClickOnce applications
Code access security for ClickOnce applications
ClickOnce and Authenticode
Trusted application deployment overview
How to: Enable ClickOnce security settings
How to: Set a security zone for a ClickOnce application
How to: Set custom permissions for a ClickOnce application
How to: Debug a ClickOnce application with restricted permissions
How to: Add a trusted publisher to a client computer for ClickOnce applications
How to: Re-sign application and deployment manifests