Vista not allowing one .exe to call another .exe

Private Declare Function CreateProcess Lib "kernel32" Alias "CreateProcessA" (ByVal lpApplicationName As String, ByVal lpCommandLine As String, lpProcessAttributes As Any, lpThreadAttributes As Any, ByVal bInheritHandles As Long, ByVal dwCreationFlags As Long, lpEnvironment As Any, ByVal lpCurrentDriectory As String, lpStartupInfo As STARTUPINFO, lpProcessInformation As PROCESS_INFORMATION) As Long

Private Declare Function WaitForSingleObject Lib "kernel32" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long

Private Type PROCESS_INFORMATION
      hProcess As Long
      hThread As Long
      dwProcessId As Long
      dwThreadId As Long
End Type

Private Type STARTUPINFO
      cb As Long
      lpReserved As String
      lpDesktop As String
      lpTitle As String
      dwX As Long
      dwY As Long
      dwXSize As Long
      dwYSize As Long
      dwXCountChars As Long
      dwYCountChars As Long
      dwFillAttribute As Long
      dwFlags As Long
      wShowWindow As Integer
      cbReserved2 As Integer
      lpReserved2 As Long
      hStdInput As Long
      hStdOutput As Long
      hStdError As Long
End Type

    Dim ProcessInformation As PROCESS_INFORMATION
    Dim StartupInformation As STARTUPINFO
    Dim ReturnValue As Long
    Dim NullString As String
    Dim AppPathString As String

    StartupInformation.cb = Len(StartupInformation)

    ReturnValue = CreateProcess(NullString, AppPathString, ByVal 0&, ByVal 0&, 1&, NORMAL_PRIORITY_CLASS, ByVal 0&, NullString, StartupInformation, ProcessInformation)
    '
    'If you need to wait for the exe to finish
    '
    Do While WaitForSingleObject(ProcessInformation.hProcess, 0) <> 0
        DoEvents
    Loop