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).

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.

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 doesn't exist, create it.

3. Add the following subkeys as String Value, if they don't 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.

   • C#
   • VB

   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 doesn't exist, create it.

3. Add the following subkeys as String Value, if they don't 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.

   • C#
   • VB

   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 aren't given the option to install solutions that aren't 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 doesn't exist, create it.

3. Add the following subkeys as String Value, if they don't 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.

   • C#
   • VB

   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.

Related content

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