Laptop Function keys

I teach a PC workshop for intermediate level users.  Many of the people at the workshop have Dell laptops.  I was encouraging those at the workshop to use Microsoft keyboard shortcuts, including those that use Function keys.  However the Dell laptops appear to provide non standard Microsoft functions and so for instance when they pressed F3 (I think it was that key) instead of the expected Microsoft action the battery charge level was shown.  What do they have to do to ensure the function keys work in a way that Microsoft works thinks they should. As far as I could see pressing the 'alt' and 'fn' keys did not help

I have seen many references to this problem in various fora etc, but can find no solution.  Does anyone know the answer?