Best option would be to backup your database regularly using MySQL dump. You can't just grab the MySQL files and restore them and expect them to work. It takes a bit more than that.
Run:
mysqldump --add-drop-table --all-databases -u username -p > mysql-backup.sql
On my Linux system I've setup a cron job to backup my databases nightly and compress the results. They then get backed up into the cloud by my backup system.
Backup is good.