PrestaShop 1.7.x - 8.x
go to "app/config" folder on your FTP and open parameters.php file in your favorite text editor PrestaShop 1.0.x - 1.6.x
go to "config" folder on your FTP and open settings.inc.php file in your favorite text editor
find the following code (or similar): 'cookie_key' => 'Q9cvUaw5tfOkriVh34KTtZiG40aTSeFWUjjVW37kIG7uhJyDEC1XdN7f',
copy & paste cookie_key value into the field below, in this showcase:
Q9cvUaw5tfOkriVh34KTtZiG40aTSeFWUjjVW37kIG7uhJyDEC1XdN7f
enter into "Your new password" field your future password with which you will be able to log into PrestaShop back-office
hit "Create MD5 string" button to generate your MD5 string
open MySQL manager (e.g. phpMyAdmin) on your webhosting
find the ps_employee database table (note: "ps_" database table prefix may be different)
find and edit the record about your account in the table. Paste and save into passwd column MD5 string from this generator
you're done
go to your PrestaShop back-office login page and use your new password in order to enter to your account
