How can I make (via API) to disable mouse (disable everywhere, not only my
app.) . I need to prevent user's mouse movement for a while, and then
re-enable it

I've been looking on February Edition of MSDN, but I didn't find anything

I'm using VB 5.0 SP3 and Windows NT workstation 4.0 SP3.

any help would be apreciated.

           Fran Arreciado

Very simple :

Hook all Windows' Mouse events using API call

HHOOK SetWindowsHookEx(
    int  idHook, // type of hook to install
    HOOKPROC  hkprc, // address of hook procedure
    HINSTANCE  hMod, // handle of application instance
    DWORD  dwThreadID  // identity of thread to install hook for
   );

with <idHook> = WM_MOUSE and <hkprc> the address of YOUR hook-procedure. ALL
mouse-events for ALL threads will then go through your procedure of you set
<dwThreadID> to 0 (zero). There you can STOP the dispatch & distribution of
the events to receiving Windows objects.

In order to stop the "freezing" process, use the API function
BOOL UnhookWindowsHookEx(
    HHOOK  hhook  // handle of hook procedure to remove
 );

With kind regards,

Koen Matthijs

Check the ShowCursor API