Am I using UDK 3 Or 4?

Hello. Recently discovered that UDK is now available for free… Was I using the earlier version, UDK 3? I was using UDK 3? Does it mean UDK 4 is now available for free, instead of This:
. Get UDK (February 2015 UDK).
I got that: . Get UDK (February 2015 UDK), for free a while ago. Was that link for UDK 3? Will UDK 4 stay free?

Your question doesn’t make sense, could you please re-phrase it?

UDK is the old Unreal Engine 3. Unreal Engine 4 is now the current and newest engine that is free to use.

UE4 never been officially called UDK and considering you talking about “February 2015 UDK”, you definitely talking about free UE3 which got update in Feb. UDK is free edition of UE3 which main difference from full licence version is you don’t have access to C++. UE4 is just UE4 and you get it via UE4 laucher, so never use UDK if you searching any UE4 material.

Help. I cannot install EU4…

This installation package is not supported by this processor type. Contact your product vendor.