Try using the Recovery discs which you should have made using the Toshiba utility when your laptop was working okay.
If you didn't make any, contact Toshiba to order a set of recovery discs for your model.
I know they supply them because I used that service last year.
If you live in Europe you can order them online: https://backupmedia.toshiba.eu/
Outside Europe I don't know the URL.