Issue the command SHOW ENGINES; to see all the different MySQL storage engines. Look for DEFAULT in the InnoDB line. Alternatively, query the INFORMATION_SCHEMA ENGINES table. (Now that InnoDB is the default MySQL storage engine, only very specialized environments might not support it.)

If InnoDB is not present, you have a mysqld binary that was compiled without InnoDB support and you need to get a different one.

If InnoDB is present but disabled, go back through your startup options and configuration file and get rid of any skip-innodb option.