I did not find a users.xml file, but rather a fileusers.xml. The contents did not tell me the user name or passwords were, but that's okay. Instead I went ahead and reinstalled, making sure to record my login password.
What I am really curious about though, is according to Kevin Yank's article 'Getting Started with Java' http://www.sitepoint.com/article/getting-started-java/2 I should download the SDK, Standard Edition. When I went looking for a download all I came accross was the Enterprise Edition. OK, I'm a sucker for site usability, and I find appropriate downloads difficult at times. The initial download page said 'Standard Edition', but then I wound up with Enterprise Edition. Whatever.
What I want to know is with EE, when I run the commands, with or without the server started, java –version or javac I get the message ' 'javac' is not recognized as an internal file command'. Do I have the wrong Java package, do I need to configure somthing else in my system (I am using windows XP), or do I just not know how to use a command prompt correctly (very likely as I have not done muc of that before).
Now that I have my passwords and usernames figured out I'll play with some more examples/articles/tutorials, and see how I go.