A invalid username/password; CMD must be run as administrator in win7 or win8

1. Enter command under DOS:
SQLPLUS SYS/Password set at installation as SYSDBA
(enter)

2. Then type the command:
alter user scott account unlock;
 

When you enter, the words “User has changed” will appear, and you can move on to the next step.  

3. Enter the command:
conn scott/tiger
 

After entering, an error message (as follows) will appear:

ERROR:
ORA-28001: The password has expired
 

Change Scott’s password

New password:

4. Enter a new password;  

5. Repeat the new password.  

Finally, there you go!

Reproduced in: https://www.cnblogs.com/dfyg-xiaoxiao/p/7213772.html