Open shell from from control panel and start mysql with this command:
mysqld –-console –-skip-grant-tables –-skip-external-locking
Open another shell from control panel and repair database with this command:
mysqlcheck -r --databases mysql --use-frm
Stop mysql, close shells and restart mysql normally.
If the database still does not start and you have a mysql backup folder, then do this:
Except for ibdata1 file, copy all content from mysql/backup folder and paste into mysql/data folder.
If you replace the ibdata1 file from mysql/data then you will get “table does not exist” error on some databases. Don’t copy the ibdata1 file!