By default, hide option is provided to all the widgets in the Customer Portal Homepage. Widgets shown in the homepage are notified in orange and those hidden would be in grey. 

1. To hide a widget, rollover your mouse on it to highlight the Visible at Home option. 
2. Uncheck the option to hide the widget from being displayed in the customer portal.
3. Click Save. 

However, if you want to show a hidden widget in the customer portal, check the Visible at Home option.