I\'m using the MessageBox class to show errors to users, and while that might not be the right behavior, it\'s very convenient. This is a touchscreen application, however,
I would create my own MessageBox class for this purpose - BigMessageBox perhaps?. It would then be a matter of replacing MessageBox.Show with BigMessageBox.Show.
Another alternative is using windows hooks to modify the form - have a look at https://web.archive.org/web/20091208060754/http://msdn.microsoft.com/en-gb/magazine/cc188920.aspx for an example from .net 1.0. This may be easier in the current release, but I can't find an example for you.