Application Verifier is a runtime verification tool for unmanaged code that assists in quickly finding subtle programming errors that can be extremely difficult to identify with normal application testing.
Application Verifier is designed specifically to detect and help debug memory corruptions and critical security vulnerabilities. It makes it easier to create reliable applications by monitoring an application's interaction with the Windows operating system, profiling its use of objects, the registry, the file system, and Win32 APIs (including heaps, handles, locks, and more). It also includes checks to predict how well the application will perform under Least-privileged User Account operation.
Running Application Verifier is easy; simply turn on the tool then run your project and go through your normal testing scenarios. When your tests are completed, view the Application Verifier logs for any errors that may have been detected.
I've been using it over the last year or so and have found several obscure bugs.