修改oracle用户密码

开始-->运行-->cmd:  
sqlplus /nolog   
运行上面命令可以登录吗?
连接到sysdba;
connect / as sysdba;  

如果不好用，可以换成用system用户登录

connect sys/password as sysdba

用户解锁
ALTER USER system ACCOUNT UNLOCK;
修改密码:  
alter user system identified by manager;

然后再试登录sqlplus
system/manager