In large or distributed organizations, it can appear difficult to distribute new versions of 4D client, if this requires distributing installers to the users and asking them to run them correctly. But where there's a network, there's an easy way to distribute information, and 4D's simple architecture makes a solution particularly easy to develop.
On the Macintosh, 4D client consists of a single application. It is usually simple to email this application to your users and ask them to delete their previous version, or for them to copy it from a file server. It would also be easy to write an Applescript to automate this, email the script to the users, and ask them to run it.
The situation is almost as simple on Windows. In this case, there are multiple files involved, but they are always kept in just two locations: the application directory itself, and the Network directory inside the 4D directory in the active System directory.
You need to install the files from the application directory in a single directory on the user's computer, and install the Network directory's contents in the same location in the active system directory on the client computer (it might be necessary to create the 4D Directory to put the Network directory in). It is probably simplest to write a batch file to copy these files from a file server, or to develop a small application using a RAD tool that does the same, but the batch file or application would be very simple, and can be customized to whatever standard layouts the user expects (perhaps there should be a shortcut to the client on the desktop, or it should be installed in the start menu in some particular place).
With a few simple steps, you can make installing even hundreds of updates to client quite easy.