The Samsung A7 USB driver makes use of the same driver as other Samsung mobile phones. The Samsung Galaxy A7 is no different to them as they all use the standard Samsung USB driver which is normally updated at least once a year. You can also find the Samsung Android driver on this website.
Note that most of the common problems with the Samsung phones have been covered on this website. The most common issue has always been that the USB is not recognised on the computer. The second is the software which is not installing. This is covered here. The download below is for the driver which will need to be installed.