John Fredrick Parker
Donor
This depends on your PoD. If it's just that the assassination attempt on Franz Ferdinand fails, no; the pan-Serb nationalists will try again and sometime they'll get caught, even if it's when they've (e.g.) distributed literature inciting rebellion rather than something as grand-scale as killing the crown prince. If it's the PoD I mentioned above, where Russia doesn't encourage Serbia as much, then yes.
If the Serbian pan-Serb nationalists aren't encouraged with Russian support for their expansionist ambitions, Russia and the United Kingdom will likely dissolve the Anglo-Russian Convention when it comes to be renewed in 1915. True, Russian power is increasing, but give it enough time (especially as the German naval threat becomes less worrying, as the British Empire's naval lead over Germany was constantly increasing at this time) and the British will be quietly searching for how to take the Russians down a peg.
But Austro-Russian disagreements over the Balkans are inevitable unless you have a PoD several decades earlier; I can talk about the reasons why at more length but that would derail this thread. So it's very difficult to imagine any great power conflict in which Austria-Hungary and Russia aren't on opposite sides.
What about a PoD after the assassination, one where Wilhelm takes his cousin's advice, and pressures the Hapsburgs to put the Serbian matter before the Hague? (FWIG, this is an idea that more or less has a great deal of support here in terms of plausibility.) If that was how OTL's WWI was prevented, would that be enough to prevent a Great War in general?