Monitor GAC changes in registry with WMI - RegistryKeyChangeEvent GACChangeNotification Not Found

Question

I'm trying to monitor the registry for changes to the GAC using WMI. I have the following code:

WqlEventQuery query = new WqlEventQuery(@"SELECT * FROM RegistryKeyChangeEvent WHERE Hive = 'HKEY_LOCAL_MACHINE' AND KeyPath='SOFTWARE\\Microsoft\\Fusion\\GACChangeNotification\\Default'");
_regWatcher = new ManagementEventWatcher(query);
_regWatcher.EventArrived += new EventArrivedEventHandler(_regWatcher_EventArrived);
_regWatcher.Start();

But when it calls Start(), it causes a ManagementException with the message "Not Found". I copied the key path from the registry so I know it exists. I have never done this before, so maybe I'm misusing it. I want to receive notification when any value is changed in the Default key (specifically when a value is added). Why is it giving the "Not Found" exception and how do I correctly monitor this key for changes using WMI?

Answer 1

You are surely yet another victim of the registry redirector in the 64-bit version of Windows. Project + Properties, Build tab, change the Platform target setting from x86 to AnyCPU. On VS2012 and up, untick the "Prefer 32-bit" checkbox.

Your program will now as a 64-bit process and can properly see the registry key. Instead of the HKLM\Software\Wow6432Node subkey you tried to look at before.