Ridiculously ASBy.
Even if Harald the great died in that unimportant battle, he had his brothers who would have raised the lands devorer and sacrified all the normans to their brother's spirit ( instead of allowing the survivors to live as slaves ). Even supposing, by whatever mean, that the saxon army at hasting had been defeated by the rabble from the continent, this was only a very small fraction of englands strengh, as most of the fyrd wasn't there. Even if ASb let the bastard vanquish england, he would have been crushed by the welsh or the scots. Both of them gave enough trouble to Harald; they would have crushed the normans without troubles.
So instead of Saxon england, you have welsh southern england and scotland encompassing northumbria. In anyway, Normans in France are crushed by Henry and the west frankish kings begin their march toward empire ( again ) using the wealth of their newly reconquered provinces, as per OTL.