How to check if Expression Encoder 4 is already install?

I faced a problem of checking a specific application is already installed. I know that I can check from the registry key for which application that is already installed but I cannot find Expression Encoder4 (window 64b开发者_StackOverflow社区it) in HKLM registry key.

Any ideas? thanks

The registry key to check is:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Expression\Encoder\4.0

I use the following code to check the encoder version and my dev computer is Windows 7 64bit:

string encoderVersion = string.Empty;
RegistryKey localKey = RegistryKey.OpenBaseKey(Microsoft.Win32.RegistryHive.LocalMachine, RegistryView.Default);
localKey = localKey.OpenSubKey(@"SOFTWARE\Microsoft\Expression\Encoder\4.0");
if (localKey != null)
{
    encoderVersion = localKey.GetValue("Version").ToString();
}