Its has some bugs , but i cant fix the bugs any one can fix this for me? TIA   Imports Microsoft.Win32 Public Class Form1       Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load         Dim networkcard As RegistryKey = Registry.LocalMachine.OpenSubKey("SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}")         Try             'Get all the network cards names and add it to Combo Box               For Each netcard In networkcard.GetSubKeyNames                  Dim networkcard2 As RegistryKey = Registry.LocalMachine.OpenSubKey("SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}\" & netcard, False, Security.AccessControl.RegistryRights.ReadKey)                 Dim networkcardname As String = networkcard2.GetValue("DriverDesc")                  ComboBox2.Items.Add(netcard)                 ComboBox1.Items.Add(networkcardname)                  networkcard2.Close()             Next             networkcard.Close()             ComboBox1.SelectedIndex = 0         Catch ex As Exception             networkcard.Close()             ComboBox1.SelectedIndex = 0         End Try     End Sub      Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged          'Get the MAC Address of the selected network card         Dim netcardnumber As String = ComboBox2.Items.Item(ComboBox1.SelectedIndex)           Dim getmac As RegistryKey = Registry.LocalMachine.OpenSubKey("SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}\" & netcardnumber, False, Security.AccessControl.RegistryRights.ReadKey)         Dim mac As String = getmac.GetValue("NetworkAddress")          TextBox1.Text = mac         getmac.Close()     End Sub      Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click         Try               Dim netcardnumber As String = ComboBox2.Items.Item(ComboBox1.SelectedIndex)             'Using integer in the above will not work              Dim chmac As RegistryKey = Registry.LocalMachine.OpenSubKey("SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}\" & netcardnumber, True)             Dim textmac As String = TextBox1.Text              If textmac.Contains("-") Then                 textmac.Replace("-", "")             End If              chmac.SetValue("NetworkAddress", textmac)              chmac.Close()              'Shell("Command.com /c IPConfig/all")              MsgBox("MAC Address changed successfully" & vbNewLine & vbNewLine & "To effect changing MAC Address you need to Disable and Renable the Network card you selected", MsgBoxStyle.Information)         Catch ex As Exception             MsgBox(ex.Message, MsgBoxStyle.Critical)         End Try     End Sub      Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click         Try             Dim netcardnumber As String = ComboBox2.Items.Item(ComboBox1.SelectedIndex)              My.Computer.Registry.LocalMachine.OpenSubKey("SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}\" & netcardnumber, True).DeleteValue("NetworkAddress")             'Shell("Command.com /c IPConfig/all")              MsgBox("MAC Address succesfully resetted" & vbNewLine & vbNewLine & "To effect changing MAC Address you need to Disable and Renable the Network card you selected", MsgBoxStyle.Information)         Catch ex As Exception             MsgBox(ex.Message, MsgBoxStyle.Critical)         End Try      End Sub End Class