I installed Netbeans and tryed to access the server's manager using: (id/pass)manager/manager, admin/admin, system/password... None of them worked.
Check the file in <TOMCAT_HOME>/conf
named tomcat-users.xml
.
If you don't find something there edit to look something like:
<?xml version='1.0' encoding='utf-8'?>
<tomcat-users>
<role rolename="admin"/>
<user username="admin" password="password" roles="standard,manager,admin"/>
</tomcat-users>