Just the Benelux and Scandinavia together are close to the size of the UK market ( from the top of my head 9,5 + 16,5 + 4,5 + 5 + 8 + 5 makes 48,5 vs 67 for UK? ) and these are fairly rich countries (probably better off than the UK). So all together not as insignificant as you make it sound.
Depends entirely on their buying habits. The UK certainly had the best demographics in the EU for Microsoft.