It's a very interesting question, mainly because of what would constitute "winning" World War 1 for the Central Powers side. That question alone confuses matters.
Would Germany even want to control all of continental Europe? Unlikely, the logistics of it are staggering. How much of the Russian Empire would they take? As mentioned before, the idea of them being able to subjugate ethnic Russians is unlikely. Here's my take:
1. Germany is still a monarchy. Hitler and the Nazis never happened. The German Empire still consists of Germany as we know it now, plus Poland, the Czech Republic, Slovakia, Denmark, the Benelux countries, the Ukraine, Belarus, Georgia, Switzerland (kind of) and maybe bits of eastern France, but not all of it. It also continues to hold significant colonies in southeast Asia and Africa. Germany today is the second largest and most powerful economy in the world next to the United States.
2. Islamic terrorism is still around, but is different, because the Ottoman Empire never really went away and Israel doesn't exist ("Poland" and Germany are the unofficial Jewish homeland for the world). Islamic extremism is entirely focussed on upstart fundamentalists fighting against the entrenched power structure of the Ottomans and similar monarchies, and rarely result in terror attacks against American or European targets. This becomes a major theatre of war, but not a world war.
3. The USSR is still around. The communist revolution happened anyway, as the Russian nascent democracy was incompetent, as was the monarchy, and led them to lose a big chunk of territory. A much stronger German Empire and USSR become closer, due to common economic interests and the fact that the communist revolution was a big help to Germany. It's still a bad place to live, but with no cold war as we know it (WW2 never happened) the Soviet economic system gets to stagger on living for longer than it should.
4. China remains a democratic republic, then a constitutional monarchy eventually, albeit a corrupt and chaotic one. 3-4 autonomous countries eventually split off from China. China still becomes a strong economy, but not the 2nd superpower it is expected to today. Japan never really develops a bubble economy, and becomes a small but strong economic force, akin to South Korea and Taiwan of today.
5. The USA becomes extremely isolationist. Canada more so, and the British Commonwealth virtually disintegrates, with most countries like Canada, Australia etc. cutting ties entirely to the UK. Canada tries to become a republic, but eventually merges with the United States. The Depression still happens though, and with no cold war alarmism socialism and communism become vital political forces in this expanded United States, which becomes a 3-4 part democracy because all the wide ranges of political beliefs. Race relations are set back at least 20 years, however, as without WW2 the world never really learns the true price of bigotry.