Can't change root password: "The system cannot find the file specified."
There are two techniques you can try:

TECHNIQUE #1

The comment from Michael - sqlbot already said it. Use double quotes

mysqladmin -u root password "Pe%8XiduwOqdZ&lt;ZFE5!"


TECHNIQUE #2

root@localhost has no password. Try running this:

mysql -uroot -e"SET SQL_LOG_BIN = 0; SET PASSWORD = PASSWORD('mynewpassword');"


This should do it as well.

CAVEAT FOR MySQL 5.6 users : TECHNIQUE #2 will not work in Linux for MySQL 5.6. There is a separate file with the temp password for root@localhost ( ${HOME}/.mysql_secret ). You login with that password and change the password from there.

Give it a Try !!!