This helped me with that password change:
1) Run upgrade.php, this is nessecearry due to the password size
2) use another browser or alternatively clear the browsers chache and cookies.
This should help you to reset an admin account. First thing you need to to; enable the password conversion, via phpMyadmin :
REPLACE INTO elkarte_settings (
[icode]variable[/icode] ,
[icode]value[/icode]
)
VALUES (
'enable_password_conversion', '1'
);
Then you can reset the admin password to a cleartext password, again via phpMyAdmin:
(mypassword is your new password, myadmin_name needs to be replaced with your admin login name)
UPDATE elkarte_members SET passwrd = 'mypassword,', password_salt ='' WHERE member_name = 'myadim_name';