Using Drupal as the CMS of choice for time now, there is a little thing assumed by the system at the first time the web site is launched which isn't welcomed in all situation: an already working mail environment.
In fact, when creating the first Drupal user (and so with administrative rights), the password is by default sent to the email address provided... even if there is no working email subsystem in order to take delivery of the random generated password. This can render the freshly installed CMS very... inefficient, don't you think?
So, in order to be able to log in, the password for this account may be directly reset to the SGBD (a MySQL data server in the following case). Here is how this can easily be achieved.
Obtain the checksum of the given string corresponding to the wanted password:
server# md5 -s padawan
MD5 ("padawan") = 9a4b83013501fde3e8864f4f4b5fb7c5
Update the password entry for the administrative account:
server# mysql -u dba_user -p drupal_database
Enter password: ********
mysql> UPDATE users SET pass = '9a4b83013501fde3e8864f4f4b5fb7c5'
-> WHERE name = 'obiwan'\g\q
Query OK, 0 rows affected (0.00 sec)
Rows matched: 1 Changed: 0 Warnings: 0
Bye
That's all: just log in as usual via the Drupal web portal, using obiwan/padawan as login/password. And be prepared to build a working mail subsystem very soon for next time...