1-->在DOS窗口下输入net stop mysql57
2-->切换到mysql的bin目录,运行mysqld --skip-grant-tables
3-->新开DOS，切换到bin目录，运行mysql -u root
4-->
use mysql
update user set password=password("new_pass") where user="root";
flush privileges;
exit;
windows下忘记root密码,布布扣,bubuko.com
原文：http://www.cnblogs.com/heystephen/p/3856527.html