CodeItBetter Programming Another VB Programming Blog

'System & API - How to get all installed Mail Applications

Option Explicit
 
Declare Function RegOpenKey Lib "advapi32.dll" Alias "RegOpenKeyA" (ByVal hKey As Long, _
    ByVal lpSubKey As String, phkResult As Long) As Long
Declare Function RegEnumKey Lib "advapi32.dll" Alias "RegEnumKeyA" (ByVal hKey As Long, _
    ByVal dwIndex As Long, ByVal lpName As String, ByVal cbName As Long) As Long
Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hKey As Long) As Long
Public Const HKEY_LOCAL_MACHINE = &H80000002
 
'Add a listbox and a command buton

Private Sub Command1_Click()
    Dim sKey As String * 255
    Dim lRegKey As Long
    Dim iKey As Integer
    List1.Clear
    Call RegOpenKey(HKEY_LOCAL_MACHINE, "Software\Clients\Mail", lRegKey)
    While RegEnumKey(lRegKey, iKey, sKey, 255) = 0
        List1.AddItem Left(sKey, InStr(sKey,  chr ( 0 ) ) - 1)
        iKey = iKey + 1
    Wend
    Call RegCloseKey(lRegKey)
End Sub