[ubuntu] ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

root@PC:/home/PC# sudo /etc/init.d/mysql stop
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service mysql stop

Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the stop(8) utility, e.g. stop mysql
mysql stop/waiting
root@PC:/home/PC# pkill -9 mysql
root@PC:/home/PC# pkill -9 mysqld
root@PC:/home/PC# pkill -9 mysqld_safe
root@PC:/home/PC# ps -ef |grep mysql
root 27690 25962 0 19:51 pts/1 00:00:00 grep --color=auto mysql
root@PC:/home/PC# kill 27690
bash: kill: (27690) - No such process
root@PC:/home/PC# kill 25962
root@PC:/home/PC# ps uaxww | grep -i mysql
PC 24175 0.7 3.8 818760 156020 ? Sl 19:29 0:10 /usr/lib/firefox/firefox /media/DA94-D856/c/How to Recover_Reset forgotten MySQL root Password on Linux _ 2daygeek.htm
root 27695 0.0 0.0 13588 944 pts/1 S+ 19:52 0:00 grep --color=auto -i mysql
root@PC:/home/PC# kill 27695
bash: kill: (27695) - No such process
root@PC:/home/PC# kill 13588
bash: kill: (13588) - No such process
root@PC:/home/PC# sudo mysqld_safe --skip-grant-tables &
[1] 27701
root@PC:/home/PC# 160518 19:53:57 mysqld_safe Can't log to error log and syslog at the same time. Remove all --log-error configuration options for --syslog to take effect.
160518 19:53:57 mysqld_safe Logging to '/var/log/mysql/error.log'.
160518 19:53:57 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
root@PC:/home/PC# mysql -uroot
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL coection id is 1
Server version: 5.5.34-0ubuntu0.12.04.1 (Ubuntu)

Copyright (c) 2000, 2013, 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> use mysql;
Reading table information for completion of table and column names
You can tu off this feature to get a quicker startup with -A

Database changed
mysql> update user set password=PASSWORD("mypw") where User='root';
Query OK, 0 rows affected (0.00 sec)
Rows matched: 3 Changed: 0 Waings: 0

mysql> update user set password=PASSWORD("newpw") where User='root';
Query OK, 3 rows affected (0.00 sec)
Rows matched: 3 Changed: 3 Waings: 0

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql> quit
Bye
root@PC:/home/PC# sudo /etc/init.d/mysql stop
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service mysql stop

Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the stop(8) utility, e.g. stop mysql
root@PC:/home/PC# sudo /etc/init.d/mysql start
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service mysql start

Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the start(8) utility, e.g. start mysql
mysql start/ruing, process 28137
root@PC:/home/PC# mysql -u root -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)