The default password of the Configuration page of Talend Administration Center is admin, you can change it by:
Go to <Tomcat installation path>/webapps/org.talend.administrator/WEB-INF/classes/ directory, look for the configuration.properties file,
Edit the following property.
# Password to access to db config page in the web-app:
The password is encrypted and stored in the configuration file, you just need to modify it with a plain text password, for example:
Save the file and restart Tomcat, the new password will be encrypted automatically in the configuration file.