Follow the steps to create theme:
- Now go for Ok.
- Now you will get the set of images if you have selected more than one if not than you'll get selected one.
- All are selected see , Now click on Fill , Go for Stretch  for Full Screen, Now click on Save Changes .
- Now you'll get default personalized window with some change, see below figure.
- There you'll be getting Unsaved Theme. Right click on that unsaved theme or Click on Save Theme button. After right click it shows two options Save Theme and Save Theme for Sharing.
- If you want to give the name of Theme than choose Save Theme option. If you want to Save theme and Share than choose second one.
- After that, choose the destination give theme and save it.