Your Firefox reported to the forum that it is an extremely ancient version. Can you check

Help > About Firefox

to see what version you really have?

Assuming you have Firefox 20 (current version), please see this article for tips on correcting the way Firefox reports itself to websites: How to reset the default user agent on Firefox.

In Firefox 20, you should find a checkbox for Do Not Track here:

orange Firefox button (or Tools menu) > Options > Privacy

More info: How do I turn on the Do Not Track feature? (this article is sensitive to the reported version of your browser, which is why you need to fix that per the above article)

Thanks for your quick response. Don't know why it took a few attempts to download newest updated version of Firefox into my computer. Finally took. Was able to use the "do not track" feature finally. Again, appreciate your help.