Declaramos las funciones del api necesarias :

Private Declare Function CreateToolhelpSnapshot Lib "Kernel32"
        Alias "CreateToolhelp32Snapshot" (ByVal lFlags As Long,ByVal lProcessID As Long) As Long

Private Declare Function ProcessFirst Lib "Kernel32" Alias "Process32First" (ByVal hSnapShot As Long, uProcess As PROCESSENTRY32) As Long

Private Declare Function ProcessNext Lib "Kernel32" Alias "Process32Next" (ByVal hSnapShot As Long, uProcess As PROCESSENTRY32) As Long

Private Declare Sub CloseHandle Lib "Kernel32" (ByVal hPass As Long)


Private Type PROCESSENTRY32
           dwSize As Long
           cntUsage As Long
           th32ProcessID As Long
           th32DefaultHeapID As Long
           th32ModuleID As Long
           cntThreads As Long
           th32ParentProcessID As Long
           pcPriClassBase As Long
           dwFlags As Long
           szExeFile As String * 260
       End Type


Para obtener la lista de tareas que se están ejecurando :


Dim hSnapShot As Long
Dim uProceso As PROCESSENTRY32
Dim res As Long

hSnapShot = CreateToolhelpSnapshot(2&, 0&)
If hSnapShot <> 0 Then
   uProceso.dwSize = Len(uProceso)
   res = ProcessFirst(hSnapShot, uProceso)
   Do While res
      List1.AddItem Left$(uProceso.szExeFile, InStr(uProceso.szExeFile, Chr$(0)) - 1)
      res = ProcessNext(hSnapShot, uProceso)
   Loop
   Call CloseHandle(hSnapShot)
End If