Its not so much the HDD but the os its self.
Its getting as far as starting it up but then it has a hissy fit and turns off!!.
You might be able to press an F key and boot it in to recovery mode if this is an option.
If this isnt you can reinstall your OS via dcd/dvd and it should side swipe your original OS into a foder of its own after install where you can access your old files and transfer tem to yur new OS.