The latest Windows version is here.
It's unclear what you are attempting to do. If the text clip is in the Videopad bin (top-left), right-click on it and Rename. 
You can also duplicate the clip and give it another name. Right-click on it, click COPY. Right-click in an open area of the bin and click PASTE CLIP.
Either the original or the copy can be Renamed. 
If this doesn't help, please follow up with the specific steps that you take.