If, by accident, you happen to delete the original "Administrator" account/user, you will need to recreate it.
INSERT INTO users (uid, name, pass) VALUES ('1', 'yourname', md5('yourpassword'));
you can also try and work with the methods below:
UID1 is the 'super admin' account.
- create a new account with user name and password of your choice : this account will initially be a regular user account, to be turned into an "Administrator" account following the next step.
- go to database table "users" and change the UID of this new account to "1" - You may now login to this account as the super admin account.
if you use phpMyAdmin for MySQL database administration, this should only take a few seconds to fix.
user_register not enabled
The above only works if the "user_register" variable is *not* set to
UPDATE variable SET value = 's:1:"1";' WHERE name = 'user_register';
DELETE FROM cache WHERE cid = 'variables';
This will change your site so that you can follow the above instructions.
Prevent account cancellation for uid 1
For Drupal 5 and 6, you may want to check out the Protect Critical Users module.
For Drupal 7, this issue will be probably solved by then. See: #46149: Prevent account cancellation for uid 1