Can't reestablish link with database

I had to reinstall my entire website. Everything worked, but I am not able to see my products and customers in the new site. I checked both of the configure.php files and the file path, name passwords to the database are correct. I checked the database and all of the data is in the database. What else might be causing the problem?

Zen Cart relies only on the database settings in the 2 configure.php files in order to connect to the database.
So, if the details in those files are wrong, then Zen Cart can't connect.

Common causes of problems:
a) you changed the database name, or username or password, and didn't update both configure.php files with the new details
b) you didn't make the files writable before you tried to upload changes to them, thus the changes didn't "take"
c) you imported a database that's using a different prefix than what you set in your configure.php files.
d) see (a), (b), and (c) above.

b) you didn't make the files writable before you tried to upload changes to them, thus the changes didn't "take"
Thanks Doc - I just needed to make the files writable. I didn't notice that they were not being updated.