How do I know my version of DBT and if I have the latest version of my Duxbury software?

There are several ways.

Launch DBT, pull down the Help Menu, and click on Check for Updates.
Subscribe to the DuxNews email list. This list only gives announcements of new products and new versions. To subscribe to duxnews, send a blank message to duxnews-request@freelists.org
Check the Duxbury Systems web site for information on DBT improvements from time to time.
Come to conferences and conventions where Duxbury Systems exhibits. These include NFB, ACB, C-SUN, CTG, CTEVH, and NBA.

As a general rule, braille software should be kept up to date so that you can take advantage of the continuous improvements that are made in the software by Duxbury Systems.