Did you get this error when running the installer downloaded from your unrealengine.com account or did this happen when installing a specific version of the engine?
It doesn’t appear as though you have a current subscription to UE4. If you go to https://www.unrealengine.com/ and create an account and sign up for the $19 / month subscription you’ll be able to download the installer there which will setup everything it needs to run however we are unable to troubleshoot install issues that have not followed that process.
In order to use the Launcher and properly access UE4, you must have created a paid subscription account on UnrealEngine.com. Once you have this, you can download the Launcher from your account page, which once installed will then download and install the UE4Editor.
We can only offer installation & setup support for users accessing the editor from the Launcher or from our GitHub repository.
Creating an account and subscribing at https://www.unrealengine.com/ will give you access to Unreal Engine 4 which is the latest version of the Unreal Engine. UDK is the previous generation of the engine and can be downloaded for free here: Unreal Engine 3 Features - Unreal Engine
Please keep in mind that the AnswerHub is meant for UE4 support and we do not support UDK on the AnswerHub.