ringbearer, if you can reply to a post you have system permission to make a new topic. Keep in mind, as has been said, Internet Explorer 8 (which is the latest version you can run in Windows xp) is not compatible with much of the new software and will not work properly. Either firefox or Chrome if updated should work fine. Microsoft apparently stopped supporting their old OS's because they want you to spend money migrating to their new systems. But xp works well for me and my office, so we just switched to chrome and no problems.
We had a couple of people who couldn't figure out where to make a new topic. If you are one of them, it's at the bottom of the list of recent topics. pick a forum, pick some topic tag words, fill in the topic title, write your topic and press submit.