for (i = 0 ; i < 2   ; i++)
          for (j = 0 ; j < NUM ; j++)
          {
               if (i == 0)
               {
                    iKeep [j] [0] = x1 = cx * (rand () % 10) ;
                    iKeep [j] [1] = y1 = cy * (rand () % 10) ;
                    iKeep [j] [2] = x2 = cx * (rand () % 10) ;
                    iKeep [j] [3] = y2 = cy * (rand () % 10) ;
               }
               else
               {
                    x1 = iKeep [NUM - 1 - j] [0] ;
                    y1 = iKeep [NUM - 1 - j] [1] ;
                    x2 = iKeep [NUM - 1 - j] [2] ;
                    y2 = iKeep [NUM - 1 - j] [3] ;
               }
               BitBlt (hdcMem,  0,  0, cx, cy, hdcScr, x1, y1, SRCCOPY) ;
               BitBlt (hdcScr, x1, y1, cx, cy, hdcScr, x2, y2, SRCCOPY) ;
               BitBlt (hdcScr, x2, y2, cx, cy, hdcMem,  0,  0, SRCCOPY) ;
                    
               Sleep (10) ;
          }
               
          DeleteDC (hdcMem) ;
          ReleaseDC (hwnd, hdcScr) ;
          DeleteObject (hBitmap) ;
             
          LockWindowUpdate (NULL) ;
     }
     return FALSE ;
}

呵呵,你该不会拿这个程序去整人吧,为什么要
置人于死地了.
若加上一个消息处理函数来接受鼠标键盘消息并返回0,不知可不可以达到要求.

根本就没有禁止,只是在屏幕上乱显示.
  可以调用BlockInput(True);禁止,但是有ctrl+alt+del 就呵呵..

你用pretranslatemessage（）函数 看看msdn他会教你怎么作的

用勾子，可能《电脑编程技巧与维护》杂志要登我的文章，《用勾子锁住系统---保护电脑使用者的眼睛》，原理是每过半个小时或一个小时，锁住鼠标和键盘5到十分钟，过了五到十分钟后解锁。