之前装的mysql5.1，但是经过系统还原后服务没有了，干脆升级到5.5，但是安装好了，配置时最后一步就是启动不了！

查看日志:programdata/data/pc.err发现：

111121 22:16:50  InnoDB: Log file .\ib_logfile0 did not exist: new to be created
InnoDB: Setting log file .\ib_logfile0 size to 10 MB
InnoDB: Database physically writes the file full: wait...
111121 22:16:50  InnoDB: Log file .\ib_logfile1 did not exist: new to be created
InnoDB: Setting log file .\ib_logfile1 size to 10 MB
InnoDB: Database physically writes the file full: wait...
111121 22:16:50 InnoDB: Cannot initialize created log files because
111121 22:16:50 InnoDB: data files are corrupt, or new data files were
111121 22:16:50 InnoDB: created when the database was started previous
111121 22:16:50 InnoDB: time but the database was not shut down
111121 22:16:50 InnoDB: normally after that.
111121 22:16:50 [ERROR] Plugin 'InnoDB' init function returned error.
111121 22:16:50 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
111121 22:16:50 [ERROR] Unknown/unsupported storage engine: INNODB
111121 22:16:50 [ERROR] Aborting

在网上一查，原来要将ib_logfile0,ib_logfile1,还有ibdata1这三个文件删掉才行，它们分别在data和programdata目录中(在配置时由你指定的)。

但是最后还是连不上，即使是服务启动了，就是连不上。

总是在第四步的security setting上提示1045 Error,死活不能连接'root'@'localhost' password[YES]

找这篇文章来:http://marclee.blog.163.com/blog/static/40317017201157101349210/ 任然不行。

没办法，退回去下载5.1的，安装顺利。

╮(╯▽╰)╭，还是老老实实用5.1吧！