How to compile an existing project for 64-bit platform?

Question

Delphi

The project is written in XE2, it took to compile to a 64-bit platform.
Found out that there is no Target Platform branch in the project that could be switched.
However, if you create a new, clean project, then there is (see screenshot) The

question is why not? And how to compile an existing project under 64 platform?

Answer 1

Try the answer from here: Cannot see the Target Platforms node in the Project...