hi, what is the use of two privilege level ? is there any performance is increase if we implement some program in the kernel space ? in linux please tell me in which space ( user or kernel ) the X11 is implemented ? why i am asking this question means if sometimes the system hangs , only the start menu ( that is k in kde ) is quickly popup's.Another reason for asking this question is my friend told the desktop in windows95 is implemented in the kernel space. please give me some useful info ( anything related to the windows or linux ). thanks bye __________________________________________________ Do You Yahoo!? Yahoo! Finance - Get real-time stock quotes http://finance.yahoo.com -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/