See if the following steps will help,
Open Control Panel -> Clock, Language, and Region -> Region and Language
1, Under 'Formats' make sure that
English - (United Kingdon) is selected
2, Under 'Location' make sure that
United Kingdom is selected
3, Under 'Keyboard and Languages' and 'Change Keyboards' make sure that the 'Default Input Device' is set to
English (United Kingdom) - United Kingdom
4, Under 'Administrative' click 'Copy Settings'. Make sure that both settings at the bottom are selected and click 'OK'
Now try in Excel to see if it has had any effect.

Note
This has helped in gaining additional settings from within certain application within Windows
OS