If the invasion of Wcotland in 1054 which established Malcolm as King of the Scots had only not happened, the son of Earl Siward, Osbeorn would not have been killed. He therefore would have succeeded his father when he died in 1055, and not Tostig. Therefore, the 'Northumbrian Revolution' of 1065 would not have happened, King Edward would not have died so soon and Edgar the Atheling would have been old enough to become king. Harald Hadraada would have had no reason to invade England and Tostig would have had no reason to be an enemy of Harold.
Plus, Scotland would have stayed gaelic. Macbeth was also (though like Malcolm) an efficient ruler.
Therefore you have no Norman Conquest and no Anglicisation of Scotland.