Make sure you open the correct hive depending on machine configuration (64 or 32 bit).
This code might work better for you;
Sub Main()
Using hklm As RegistryKey = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, IIf(Environment.Is64BitOperatingSystem, RegistryView.Registry64, RegistryView.Registry32))
Using key As RegistryKey = hklm.OpenSubKey("SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-18\Products")
Console.WriteLine(key)
End Using
End Using
End Sub
Hope this helps,
Fredrik