I have just run into the same problem but I fixed it by doing the following:
1. Go back to phpmyadmin (The url should be similar to this : http://localhost:8080/phpmyadmin/)
2. Click your database name in order to display tables
3. Choose the table wp_users (if you’ve changed the wp_ prefix to something else when installing wordpress,
then it should be “yourNewPrefix_users”.) and click on it to open rows.
4. You will just notice that it has only one row. What you have to do is to click “edit” in order to edit columns
5. Some columns will pop up. Only one column causes the password issue: the column name is as follow:
user_pass | varchar(255) | box (please click on it and select MD5 | box (just delete whatever
you see in that box) and type any password (it may be your old password that did not work for you
previously while attempting to login) and hit Go to save your changes.
6. go back to your browser now and try to login again to wp-admin