Your link is not correct as it is missing the "Itemid" parameter.
It should be:
http://computers.excel.net/index.php?option=com_hikashop&view=category&layout=listing&Itemid=XXX
where XXX is the id of your category listing menu (and by the way, the screenshot of your menu's options indicates that you configured your menu as a products listing since the type of content option is set to product).
So do two things:
1. change back the type of the menu to "category".
2. add the id of the menu in your link as explained above.