HELP PLEASE!!! blue screen with white rays stuck

There is a moving cursor but nothing else happens. the login page does not appear. The screen background just stays blue with white rays. I do not want to lose any files. What can I do ?

I would recommend going through the steps for http://www.sevenforums.com/tutorials/219533-troubleshooting-windows-7-failure-boot.html, and post back the results of each step to see if we have further troubleshooting steps.