You can choose how the C1Expander control appears on the form initially using the Expanded property. By default the Expanded property is set to True and the control initially appears expanded when the page is loaded. You can set the Expanded property to False to set the control to initially appear collapsed when the page is loaded.

So, for example, in the Aristo theme:

Expanded Setting	Initial State Preview
True (default)
False

You can set the Expanded property in the C1Expander Tasks menu, in the Properties window, in Source view, and in Code. To set the Expanded property in the C1Expander Tasks menu, uncheck or check the Expanded box: