009.mysql-windows下mysql卸载不干净导致的，安装已经存在The service already exists!

C:WINDOWSsystem32>mysqld --install mysql8
The service already exists!
The current server installed: E:mysqlmysql-5.6.42-winx64inmysqld mysql8

查看 是否有旧的mysql服务进程
C:WINDOWSsystem32>sc query mysql

SERVICE_NAME: mysql
        TYPE               : 10  WIN32_OWN_PROCESS
        STATE              : 1  STOPPED
        WIN32_EXIT_CODE    : 0  (0x0)
        SERVICE_EXIT_CODE  : 0  (0x0)
        CHECKPOINT         : 0x0
        WAIT_HINT          : 0x7d0

删除服务
C:WINDOWSsystem32>sc delete mysql
[SC] DeleteService 成功

C:WINDOWSsystem32>sc delete mysql8
[SC] DeleteService 成功

C:WINDOWSsystem32>sc delete MySQL
[SC] DeleteService 失败 1072:

指定的服务已标记为删除。

重新安装mysql8