Start at the beginning, did this happen out of no-where on the system or did something happen before the issue? Was the system running very slow, drive making noise, etc...? You should list your exact model not just Samsung. Did you try anything to fix this already?
Often an issue like this is a sign of a failed hard drive although recently MS has been very bad with patches that cause computer boot issues.
Not with a repair setup, and not if you don't format the drive even if you do a full setup. If a repair setup does not work, a clean Windows setup will, but you will need to make sure your files are backed up and you have your program installation media around to re-install things.