On menu bar click File - Save With Options. In the window that pops up, click on radio button Save for Previous (7.0). To save to 6.1, you have to first save from 7.1 to 7.0. Then open the 7.0 version with LV7.0. Repeat the procedure, but this time Save for Previous will be to 6.1. Voila, you're done. Each time you save to a previous version, LV creates a new folder under the folder that the vi lies in. The previous version vi is located inside this newly created folder. That way, the original vi is unchanged, and you have copies in different LV versions.