1. After loading your first video file into ConvertXtoDVD, right click on the titleset and select "merge more files to this titleset".

2. In the Titleset content editor that will appear, you will see the first video file in the queue list as #1. Now click on the merge button in the very right column to select a video file to be added/joined or drag and drop the video file to the corresponding place.

The added video file will now appear in the queue list as #2, right next to the first file #1, in the chronological order in which they will play. If you have additional audio tracks and/or subtitle files you can add them below the corresponding video file in this window.

Click OK (right bottom) once you're done, this window closes, and the added file(s) will appear under Source file(s) info in your project.

Note: Every merged file adds automatically an start chapter point in the titleset(all merged files make a chapter at merge point) and the maximum number of files that can be merged is 99.