V or C#

I currently run a website for a sports association. They currently enter results via cpanel webpage I created for them via PHP. I want to move them over to a more advanced Windows based system using MySql. The database is also used on the website via PHP.

What language should I be using to create a Windows based application for the office to enter in tournaments, results, address information, player information etc etc et directly into the MySQL DB, VB or C#?


Regards,
David