My computer updated automatically and prompted for restart. Once restarted, the computer froze at the blue Windows is starting screen. Tried to restart and got same thing. Tried to reinstall Windows XP and had great difficulty in getting it to go all the way through. Said it couldn't find several files, but finally completed. Still goes to blue starting screen and stops. Considered upgrading to Windows 7, but have been told that all files will be lost. Cannot get to start in Safe Mode, so no option to get in and get necessary files. Any suggestions?