if it won't even start in safe mode the option you really have is to put the windows CD in the drive and attempt to repair the windows installation.
To do this put the CD in the drive, restart the computer and when it prompts you to press any key to boot from cd press any key. then at the first blue screen that you get options hit enter to install windows, don't hit R for repair at this point. I can't remember the exact details but at one of the subsequent screens you will have the option to repair the existing windows installation, select this option and windows will attempt to repair itself.
Obviously nothing is 100% certain but doing this should result in your windows installation being repaired and coming back to life with all data, programs and setting just as they where before.