dotnet - Enumerating a Registry Key Results in a Null Value

Published: Dotnet Estimated reading time: ~1 minutes

This post assumes .NET 4.0

After trying for some time to get a registry key to list all of its subkeys, I kept getting a null value back.

This code does not work It always returns null.

var keyName = @"SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileGuid";

using (var guidSet = Registry.LocalMachine.OpenSubKey(keyName))
{
 if (guidSet != null)
 {
  foreach (var guid in guidSet.GetSubKeyNames())
  {
   result.Add(guid);
   Console.WriteLine("{0}", guid);
  }
 }
}

This code works

var keyName = @"SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileGuid";

using (var hklm = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry64))
using (var guidSet =hklm.OpenSubKey(keyName))
{
 if (guidSet != null)
 {
  foreach (var guid in guidSet.GetSubKeyNames())
  {
   result.Add(guid);
   Console.WriteLine("{0}", guid);
  }
 }
}

The difference is that the working code targets the x64 portion of the registry while the non-working code targets the default portion of the registry.

In this particular case, the ProfileGuid subkey does not exist is the WOW6432Node subkey of the registry.