1. 从MySQL官网下载免安装的压缩包mysql-5.7.21-winx64.zip
2. 解压到相应的目录（此处解压到F:\mysql-5.7.21-winx64）
3. 配置环境变量，将MySQL的启动目录（F:\mysql-5.7.21-winx64\bin）添加到Path中
4. 在MySQL目录下（F:\mysql-5.7.21-winx64）创建my.ini文件，内容如下：
[mysql]
# 设置mysql客户端默认字符集
default-character-set=utf8
[mysqld]
#设置3306端口
port = 3306
# 设置mysql的安装目录
basedir=F:\mysql-5.7.21-winx64
# 设置mysql数据库的数据的存放目录
datadir=F:\mysql-5.7.21-winx64\data
# 允许最大连接数
max_connections=200
# 服务端使用的字符集默认为8比特编码的latin1字符集
character-set-server=utf8
# 创建新表时将使用的默认存储引擎
default-storage-engine=INNODB
5. 管理员身份运行cmd
切换目录：
C:\Windows\system32>cd F:\mysql-5.7.21-winx64\bin
生成MySQL服务：
F:\mysql-5.7.21-winx64\bin>mysqld -install
Service successfully installed.
生成data目录：F:\mysql-5.7.21-winx64\bin>mysqld --initialize-insecure --user=mysql
启动MySQL服务：
C:\Windows\system32>net start mysql
MySQL 服务正在启动 .
MySQL 服务已经启动成功。
6. 登录数据库，修改密码（默认密码为空）
登录数据库：
C:\Windows\system32>mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.21 MySQL Community Server (GPL)
Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
修改密码：
mysql>
mysql>
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
+--------------------+
4 rows in set (0.00 sec)
mysql> use mysql;
Database changed
mysql> update user set authentication_string=password("新密码") where User="root";
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 1
mysql>
mysql>FLUSH PRIVILEGES;