How to read a value from a registry key

I tried to use the same code and also did not return any value, although the key exists in the Registry of Windows. I tried it this way:

Dim regKey = My.Computer.Registry.LocalMachine.OpenSubKey(
   "SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkList\NewNetworks")
Dim value = regKey.GetValue("NetworkList")

But it gave error in the second line, saying that the variable regKey contained no value (exception Object reference not set to an instance of an object ).

I then ran Sysinternals' Process Monitor , filtering only Registry and found that the program was actually trying to access this key (note the subkey that was added): HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\NetworkList\NewNetworks .

My Windows is 64-bit, so I soon figured the program was running in 32-bit. To be sure, I put two labels on the Form to check for two things, if the operating system was 64-bit and if the application was 64-bit:

   Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load

      Is64BitOsLabel.Text = $"Is 64-bit OS: {Environment.Is64BitOperatingSystem}"
      Is64BitAppLabel.Text = $"Is 64-bit App: {Is64BitApp()}"

   End Sub

   Private Function Is64BitApp() As Boolean

      Return IntPtr.Size = 8

   End Function

(The code for the function Is64BitApp() I found here )

I then confirmed that the OS was 64-bit, but the application was not, although the Target CPU of my project was marked as AnyCPU . It was then that I noticed the Prefer 32-bit option, just below the Target CPU option in Project properties > Compile , which was already checked when I created the project. I unchecked this option and then the application started to run as 64-bit.

I tried again to access the registry key and this time it was found, but then it started to give the Requested registry access is not allowed exception, because I was trying to access HKEY_LOCAL_MACHINE with an ordinary user. I ran Visual Studio as an administrator and it finally worked.

The only thing that did not work was the display of the returned value in a MsgBox , as you did, because since this value is of type REG_MULTI_SZ , the returned type was String() .

EDIT:
Then I discovered that I would not even need to have created the Is64BitApp() function because, in addition to the Environment.Is64BitOperatingSystem property I used in the code, there is also the Environment.Is64BitProcess property:

  

Environment.Is64BitProcess Property
link

After this question the user jnmoura did another, which I also answered, which complements a bit this, so I will leave here as a reference:

  

Access 64-bit key in Windows Registry through 32-bit application

I left it this way:

 Private Sub ObterTipoDaRede()
    Dim pRegKey As RegistryKey = Registry.LocalMachine
    pRegKey = pRegKey.OpenSubKey("SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkList\NewNetworks")
    Dim val As Object = pRegKey.GetValue("NetworkList")
    Me.teste = val
End Sub


Public Sub Preencher_Grid_dgvDadosComputador(Grid As Object)
    With Grid
        .Rows.Add("Nome_Do_Computador ", Me.NomeMaquina)
        .Rows.Add("Nome_Domínio ", Me.DominioMaquina)
        .Rows.Add("Pasta_(Moura_)", Me.PastaMoura)
        .Rows.Add("Firewall_Redes/Domínio", Me.FirewallRedesDominio)
        .Rows.Add("Firewall_Redes/Privadas", Me.FirewallRedesPrivadas)
        .Rows.Add("Firewall_Redes/Publicas", Me.FireWallRedesPublicasConvidadas)
        .Rows.Add("teste", Me.teste)
    End With
End Sub

In the constructor I call the sub

Public Sub New()

    ObterTipoDaRede()

End Sub

And in the form load I call the procedure to populate the datagrid

 Dim Analise As New Analisar()


Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    Analise.Preencher_Grid_dgvDadosComputador(dgvDadosComputador)

End Sub