Since ever when installing from war on a fresh system after the installation we have in System configuration a button to install as a service. 

In version 2.504.2 today it was not present. Few days ago an indian collegue faced the same issue and finally she installed using a windows installer.

But as since ever I am using war installation to do so I investigated a little bit so despite several repetitions of installations the button never appeared... I was disturbed since few weeks (not so much) ago I installed two other fresh servers without any problems. 

So I tried to get an older version of the war to do that installation. In the case I started back from quite old 2.452.2 and after all installation process there was no issue to get the "install as a service" button. So it is little if it is missing in very recent war versions (at least 2.504.*)

I feel it is bug and even a major bug so I report it