From where I can access the Zenler Studio interface?

Zenler Studio > Support Help
If you are using PowerPoint 2010/2007, you'll find a new tab/ribbon named Zenler Studio. In the case of XP/2003 you can find a toolbar named Zenler Studio. If you are using 2010/2007 you can find the Zenler Studio tab in PowerPoint ribbon. See Zenler Studio tab as shown below:

Zenler Studio in PowerPoint 2010/2013


Zenler Studio in PowerPoint 2007



Zenler Studio in PowerPoint 2003