Option Explicit
Private Declare Function mciSendString Lib "winmm.dll" Alias "mciSendStringA" (ByVal lpstrCommand As String, ByVal lpstrReturnString As String, ByVal uReturnLength As Long, ByVal hwndCallback As Long) As Long
Private Sub Command1_Click()
mciSendString "close avi", 0, 0, 0
mciSendString "open c:\123.avi alias avi", 0, 0, 0
mciSendString "play avi fullscreen", 0, 0, 0
End Sub