hi, thanks Dapper Dan, for answering. It seems that the problem is related to my video card an ATI 9800 PRO. I spend the entire day seaching the web for a solution. until i found it. Have to boot linux in text mode and login as root, then edit XF86, in my video card driver section change from radeon driver to vesa. After that reboot the system and bingo it runs fine. At last i install the driver from ati and problem solve. Thanks for your interst in helping me. I hope this can help other people with the same problem as me.