A long update it crashed--black screen no cursor.

laptop has been idle for a year as I bought a desktop. I needed it for a job so cleaned and charged it. started up dating everything . It was going so well then on a long update it crashed--black screen no cursor. seemed to recover then I got -current password. I've never used a password on startup. so that's where I am. I'm not concerned about data,that's on the desktop. can I replace the hard drive and will that sort it. thanks, auldreekie