Not losing the Hundred Years' War?
The succession of conflicts (not only HYW, but as well the "first HYW" before), points that it wasn't winnable, assuming we understood union of the crown as the objective of the war.
At worst, it would have turned into a war of attrition, and while France had really divided periods up to civil war, it benefited from serious resources' advantage, demographically, military and fiscally-wise.
England did held up more than honorably on this regard, but with a Parliament hostile to spend English resources about it, it only deepened this gap.
There's a reason why the war lasted decades, or why Plantagenets preferred to make truce and peace of compromise as Brétigny as more realistic objectives while they clearly had the upper hand, over taking over the french crown with dubious rights.
Now, at best, a PoD where Charles VII dies before his sacre would certainly help. Armagnacs would have loss their main rally banner : it doesn't mean that a conquest is possible, but I could see the 2/3 of France under Charles VII's rule to eventually accept to recognize Henri II/VI as king even if more or less nominally.
That said, it means no UK to speak of ITTL : at best, it would have ended with an uneasy personal union where French part would get too much importance on regard to England (probably ending the same way than Spanish-Portugal union, except England would probably plays the junior partner there).
If England can't secure resources to counterbalance continental pressure (as it with with colonial resources), mainland holdings are likely to be took over.