f something goes wrong when InnoDB attempts to initialize its tablespace or its log files, delete all files created by InnoDB: all ibdata files and all ib_logfile files. If you already created some InnoDB tables, also delete the corresponding .frm files for these tables, and any .ibd files if you are using multiple tablespaces, from the MySQL database directories. Then try the InnoDB database creation again. For easiest troubleshooting, start the MySQL server from a command prompt so that you see what is happening.
111019 8:17:24 [Note] Plugin 'FEDERATED' is disabled. 111019 8:17:25 InnoDB: The InnoDB memory heap is disabled 111019 8:17:25 InnoDB: Mutexes and rw_locks use Windows interlocked functions 111019 8:17:25 InnoDB: Compressed tables use zlib 1.2.3 111019 8:17:26 InnoDB: Initializing buffer pool, size = 225.0M 111019 8:17:27 InnoDB: Completed initialization of buffer pool 111019 8:17:27 InnoDB: highest supported file format is Barracuda. InnoDB: No valid checkpoint found. InnoDB: If this error appears when you are creating an InnoDB database, InnoDB: the problem may be that during an earlier attempt you managed InnoDB: to create the InnoDB data files, but log file creation failed. InnoDB: If that is the case, please refer to InnoDB: http://dev.mysql.com/doc/refman/5.5/en/error-creating-innodb.html 111019 8:17:27 [ERROR] Plugin 'InnoDB' init function returned error. 111019 8:17:27 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed. 111019 8:17:27 [ERROR] Unknown/unsupported storage engine: INNODB 111019 8:17:27 [ERROR] Aborting
111019 8:17:27 [Note] C:\Program Files\MySQL\MySQL Server 5.5\bin\mysqld: Shutdown complete