Installation files might be missing

Hi guys,

Am I missing some files during the installation or what because it seems like I’m missing some features. For example the Coupon Code feature it’s not in promotion. In the Admin setting there is no Suppliers and there is no Update either. I know there was couple of errors when I uploaded the files to my server. Does re-installing help. If so, How can I re-install without losing my datas and current settings.