Devel Ver 3 worked - CI3 broken on live host

Offtopic, I would not trust any login credentials for live servers etc on such an old and abandoned Operating system like XP.

Your problem is related to the server PHP configuration. Clearly you have access to the server config files but not the needed experience. Perhaps the best advise is to run it on a shared hosting account from company X or Y or on a managed (virtual) server.