What is the default username and password in Tomcat?

I installed Netbeans and tryed to access the server's manager using: (id/pass)manager/manager, admin/admin, system/password... None of them worked.

Solution

My answer is tested on Windows 7 with installation of NetBeans IDE 6.9.1 which has bundled Tomcat version 6.0.26. The instruction may work with other tomcat versions according to my opinion.

If you are starting the Apache Tomcat server from the Servers panel in NetBeans IDE then you shall know that the Catalina base and config files used by NetBeans IDE to start the Tomcat server are kept at a different location.

Steps to know the catalina base directory for your installation:

Right click on the Apache Tomcat node in Servers panel and choose properties option in the context menu. This will open a dialog box named Servers.
Check the directory name of the field Catalina Base, this is that directory where the current conf/tomcat-users.xml is located and which you want to open and read.
(In my case it is C:\Users\Tushar Joshi\.netbeans\6.9\apache-tomcat-6.0.26_base )
Open this directory in My Computer and go to the conf directory where you will find the actual tomcat-users.xml file used by NetBeans IDE. NetBeans IDE comes configured with one default password with username="ide" and some random password, you may change this username and password if you want or use it for your login also
This dialog box also have username and password field which are populated with these default username and password and NetBeans IDE also offers you to open the manager application by right clicking on the manager node under the Apache Tomcat node in Servers panel
The only problem with the NetBeans IDE is it tries to open the URL http://localhost:8084/manager/ which shall be http://localhost:8084/manager/html now