To resolve this error, please go into the following location:
C:\Documents and Settings\All Users\Application Data\MySQL\MySQL Server 5.1\Data
and delete “ib_logfile0″ and “ib_logfile1″.
Then go to Services and start your MySql. It will resolve the error and start you MySql.
Why: According to my search: Open the my.ini file and check the InnoDB variables’s size. When above file exides the mentioned size it will prompt this(“Plugin ‘InnoDB’ registration as a STORAGE ENGINE failed.”) error.