how to uncheck single checkboxes

I'm sorry but are you referring to the default selection of a checkbox? There's a settings that you can modify to set the checkbox to selected or not. Also you can untick the box by clicking it again.

If this is not what you are referring to kindly tell us more about your concern.

I'd like to only show 1 checkbox (not the default of 3) and be able to uncheck the single checkbox. It always reverts back to showing 3 options and no checkboxes unmarked.
Essentially..
I start with the default 3
I try to edit it to show just 1 without any text
Then I try to turn off checkbox from "select" state to "un-selected"
Problems I have:
1. I cannot un-select the single text box without any text
2. It reverts back to show all 3 default options after I exit and return to the form to edit it
...

Use empty space hack to accomplish that. In the options section, put:  

Hope that helps!

How about using the Radio Button field instead of the checkbox and the Options to "YES and NO", for example:

 

Let us know if you need further assistance.

Thanks

@britelabs

I've moved your question to a separate thread in order to properly address it.
You'll be answered here: http://www.jotform.com/answers/596170