首先停止mysql

C:\Program Files\MySQL\bin>net stop mysql

MySQL 服务正在停止.
MySQL 服务已成功停止。

然后使用mysql bin目录的mysqld-nt.exe 执行命令 mysqld-net –skip-grant-tables

C:\Program Files\MySQL\bin>mysqld-nt.exe –skip-grant-tables

新开cmd，再次跳转到bin目录，输入mysql，即登录成功，后续就是自己修改密码之类的；

C:\Program Files\MySQL\bin>mysql

Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.0.91-community-nt MySQL Community Edition (GPL)

Type ‘help;’ or ‘\h’ for help. Type ‘\c’ to clear the current input statement.

mysql>