basically if Hiter was not nuts and let his scientists and military experts run the war, the outcome may have been different. Hitler was obsessed with his own propaganda that said the US & UK were weak, lazy etc. and would get tired of a long war, make peace like France, and Germany could keep territory siezed already. Hitler made a mistake attacking Russia too soon, before the UK was defeated, instead could have possibly convinced the UK, France, etc that Russia was a threat and shifted a german alliance with West Europe. Our history fails to remind us that WW2 started when both Russia and Germany attacked, invaded and annexed Poland, next Russia invaded Finland followed by Germany invading Norway. Hitler failed when he broke the pact with Russia, who then basically switched sides from Axis to Allies; if Hitler could have made a pact with Allies to fight Russia instead, then your scenerio of a Hitler 'win' would be feasible.
German scientists had a number of advances in WW2 that could have 'won' the war, and nearly developed a nuclear bomb years before the US manhattan project began, were very close to success but the project was not given much funding. Hitler was obsessed with insanely expensive V1 & V2 revenge weapons, that were basically useless strategically, but he thought he could 'scare' england into surrender with these noisy toys. germany also produced a long range bomber capable of a round trip from berlin to NY, but this was never mass produced. hitler foolishly turned german jet fighter into another revenge weapon bomber, and lost his chance at air superiority. hitler also wasted money on huge stupid mega projects, like the Bismark battleship that was promptly sunk after completion, rather than building more of the advanced submarines that could have been more effective if produced in greater numbers. Germany also had excellent tanks, but far too few of them, and each was uniquely crafted, and parts were not interchangeable, even simple items like oil filters required a custom part for each model, making maintenance a nightmare. The US mass produced tanks, trucks, PT boats, busses, etc that all used the same motors and parts, making maintenance easy.