[DotNetDevelopment] Getting values out of the registry for 64 bit machines

[MyPrettyPony]

I used to use the following code to get an installation directory for
a file. The problem arises when the key is on a 64bit machine it is no
longer in CLSID\\guid\\InProcServer32" but in \Wow6432Node\CLSID\guid
\InprocServer32.

Is there a better windows api call that I can make so I don't have to
make this check twice?

public static string GetInstallationDirectory()
{
string directory = string.Empty;
try
{
        RegistryKey key = Registry.ClassesRoot.OpenSubKey("somekey");
        if (key != null)
        {
                string className = Convert.ToString(key.GetValue(string.Empty));
                if (!string.IsNullOrEmpty(className))
                {
                        key = 
Registry.ClassesRoot.OpenSubKey(string.Format("CLSID\\{0}\
\InProcServer32", className));
                        if (key != null)
                        {
                                string path = 
Convert.ToString(key.GetValue(string.Empty));
                                if (!string.IsNullOrEmpty(path))
                                        directory = Path.GetDirectoryName(path);
                        }

                }
                if (key != null)
                        key.Close();
        }
}
catch (System.Security.SecurityException ex)
{

}
return directory;
}