In this case, open your database administration tool (e.g. phpMyAdmin), switch to table tl_user of the TYPOlight database and edit the record that corresponds to your TYPOlight administrator account. Set a new password and choose the SHA1 function to encrypt the password from the drop down menu on the left hand side of the input field. If this does not work, enter the following code:

8e0107bf1c7fbeef6538dff7173aa458e7dd585e:8c37627a0e2c606189e7765

The code above is the encrypted version of the password reset123, which you can then use to log into the back end.