I am sure, he would have found solution in the following way
1. Locate the group name Admin> Tools > Banner Management
and click the status button, which change from Green to Red, where Green is Active and Red is deactivate, hence if you gave multiple groups created it means that you gave that number of images associated in the footer
please refer to my image A which points out all the group records associated with the Footer banner image
Those all 4 images (i mean since we have 4 entries for the same group name) are shown randomly
2. Now if we want to disable any of those banner then please deactivate the appropriate row which that the image
3. If we need to totally disable the Footer banner then it is in different selection
Admin > Configuration > Layout section
Select the Records which represent footer entry and remove the group name by editing the record.
please refer image B



