OpenSubKey under HKLM\Software returning null

Question

Here's my code:

Microsoft.Win32.RegistryKey key = Microsoft.Win32.Registry.LocalMachine.OpenSubKey(@"SOFTWARE\ADM");

The registry entry exists on the machine. key is always null.

I don't think that this is a security issue. I'm running as Administrator. (I've even explicitly ran the assembly under Administrator mode).

I'm using Visual Studio 2010 running on Windows 7 64bit.

Answer 1

The problem is that I'm running 64bit and my app is compiled as 32bit.

The key being read by:

Microsoft.Win32.RegistryKey key = Microsoft.Win32.Registry.LocalMachine.OpenSubKey(@"SOFTWARE");

Is not HKLM\SOFTWARE but instead *HKLM\SOFTWARE\Wow6432Node*. Compiling the application as x64 solves the problem.

Answer 2

I've run your code with a different application name (one I have a key for) and everything was ok, so the code is ok, but I tested this on Win XP.

When studying writing to the registry, I found this article about registry virtualization in Windows 7 that might cause your problems:

Windows Vista and later versions of Windows improve application compatibility for these applications by automatically redirecting these operations. For example, registry operations to the global store (HKEY_LOCAL_MACHINE\Software) are redirected to a per-user location within the user's profile known as the virtual store (HKEY_USERS\_Classes\VirtualStore\Machine\Software).