I found out that the search function wasnt correctly installed. Though i couldnt find how to reinstall the complete core search module, Im just going to use the google search for the time being unless anyone knows how to reinstall it.
If you mean want to uninstall the RokAjaxSearch, you can go to Extensions >> Install/Uninstall, then go to "Modules" tab, choose the RokAjaxSearch module and click uninstall button.
After that, you may try to re-install it again