I'm attempting to intercept and interrupt mouse events. Lets say I wanted to disable the right mouse button down event, or even the mouse move event. I haven't been able to figure out the interrupting part. I am using the (I assume pretty widely used) following code for Global Hooking of the mouse. Private Structure MSLLHOOKSTRUCT Public pt As Point Public mouseData As Int32 Public flags As Int32 Public time As Int32 Public extra As IntPtr End Structure Private _mouseHook As IntPtr Private Const WH_MOUSE_LL As Int32 = 14 Private Delegate Function MouseHookDelegate(ByVal nCode As Int32, ByVal wParam As IntPtr, ByRef lParam As MSLLHOOKSTRUCT) As Int32 <MarshalAs(UnmanagedType.FunctionPtr)> Private _mouseProc As MouseHookDelegate Private Declare Function SetWindowsHookExW Lib "user32.dll" (ByVal idHook As Int32, ByVal HookProc As MouseHookDelegate, ByVal hInstance As IntPtr, ByVal wParam As Int32) As IntPtr Private Declare Function UnhookWindowsHookEx Lib "user32.dll" (ByVal hook As IntPtr) As Boolean Private Declare Function CallNextHookEx Lib "user32.dll" (ByVal idHook As Int32, ByVal nCode As Int32, ByVal wParam As IntPtr, ByRef lParam As MSLLHOOKSTRUCT) As Int32 Private Declare Function GetCurrentThreadId Lib "kernel32.dll" () As Integer Private Declare Function GetModuleHandleW Lib "kernel32.dll" (ByVal fakezero As IntPtr) As IntPtr Public Function HookMouse() As Boolean Debug.Print("Mouse Hooked") If _mouseHook = IntPtr.Zero Then _mouseProc = New MouseHookDelegate(AddressOf MouseHookProc) _mouseHook = SetWindowsHookExW(WH_MOUSE_LL, _mouseProc, GetModuleHandleW(IntPtr.Zero), 0) End If Return _mouseHook <> IntPtr.Zero End Function Public Sub UnHookMouse() Debug.Print("Mouse UnHooked") If _mouseHook = IntPtr.Zero Then Return UnhookWindowsHookEx(_mouseHook) _mouseHook = IntPtr.Zero End Sub Private Function MouseHookProc(ByVal nCode As Int32, ByVal wParam As IntPtr, ByRef lParam As MSLLHOOKSTRUCT) As Int32 'Debug.Print("Message = {0}, x={1}, y={2}", wParam.ToInt32, lParam.pt.X, lParam.pt.Y) If wParam.ToInt32 = 513 Then '''interrupt the left mouse button event here, but don't know what to return to do so. End If Return CallNextHookEx(WH_MOUSE_LL, nCode, wParam, lParam) End Function