Hi!
The IsZoomed function determines whether the window is maximized,
the IsIconic function determines whether the window is minimized.

Declare Function IsZoomed Lib "user32" (ByVal hwnd As Long) As Long
Declare Function IsIconic Lib "user32" (ByVal hwnd As Long) As Long

GetWindowPlacement also retrieves the show state of window into ShowCmd member of structure:

Private Const SW_SHOWNORMAL = 1
Private Const SW_MAXIMIZE = 3
Private Const SW_MINIMIZE = 6
Private Type POINTAPI
        x As Long
        y As Long
End Type
Private Type RECT
        Left As Long
        Top As Long
        Right As Long
        Bottom As Long
End Type
Private Type WINDOWPLACEMENT
        Length As Long
        flags As Long
        showCmd As Long
        ptMinPosition As POINTAPI
        ptMaxPosition As POINTAPI
        rcNormalPosition As RECT
End Type
Private Declare Function GetWindowPlacement Lib "user32" (ByVal hwnd As Long, lpwndpl As WINDOWPLACEMENT) As Long

>I would like to know how to get WindowState by API from his hwnd