My 1.25 Mini w/ 512 RAM running 10.3.9 won't start up. Last night I installed the old security update went to bed. When I went to turn it on, I got to the login screen, clicked on my user name, then the login window disappeared and nothing happened. When I did a hard reboot, it got through the Apple screen then went to a blue desktop with only a mouse cursor. What should I do?