Windows failing to boot up.

When my computer boots up it doesn't load windows as normal, it goes to a screen which says "Sorry for the inconvenience..." then gives me options to restart windows in safe mode, safe mode with networking, the last working configuration, command prompt or start windows normally.
Whichever option I pick, it just restarts and goes back to that screen.

Someone told me to start windows back up with the windows cd, but even when I put the cd in , the same thing occurs.

And will I be at risk of losing all my data if I do reinstall windows?

Much appreciated, thank you for your time.