How to: Determine if a Value Exists in a Registry Key in Visual Basic
The GetValue method of the My.Computer.Registry object can be used to determine whether a given value exists in a specific registry key.
When reading the registry from a Web application, the current user depends on the authentication and impersonation implemented in the Web application.
To determine whether a value exists in a registry key
Use the GetValue method to retrieve the value. The following code checks the value and returns a message if it does not exist.
If My.Computer.Registry.GetValue("HKEY_LOCAL_MACHINE\TestApp", "TestValue", Nothing) Is Nothing Then MsgBox("Value does not exist.") End If
Robust Programming
The following conditions may cause an exception:
The name of the key is Nothing (ArgumentNullException).
The user does not have permissions to create registry keys (SecurityException).
The key name exceeds the 255-character limit (ArgumentException).
The key is closed (IOException).
The registry key is read-only (UnauthorizedAccessException).
Security
To run this process, your assembly requires a privilege level granted by the RegistryPermission class. If you are running in a partial-trust context, the process might throw an exception due to insufficient privileges. Similarly, the user must have the correct access control lists for creating or writing to settings. For example, a local application that has the code access security permission might not have operating system permission. For more information, see Code Access Security Basics.
See Also
Tasks
Troubleshooting: Manipulating the Registry (Visual Basic)