The default password of the Configuration page of Talend Administration Center is admin. You can change it using these steps:
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: database.config.password=8c6976e5b5410415bde908bd4dee15df,Encrypt
The password is encrypted and stored in the configuration file, you just need to modify it with a plain text password, for example:
# Password to access to db config page in the web-app: database.config.password=newPassword
Save the file and restart Tomcat. The new password will be encrypted automatically in the configuration file.