1.net stop mysql
2.my.ini中[mysqld]plugin_dir的下面增加skip-grant-tables
3.net start mysql
4.在Navicat中打开mysql数据库执行：UPDATE `user` SET Password = password (‘new-password‘) WHERE User= ‘root‘;
5.在my.ini中[mysqld]plugin_dir的下面去掉skip-grant-tables
6.关闭mysql服务，重新启动mysql服务
原文：http://www.cnblogs.com/daviddong/p/5924423.html