Refresh fontfamily.families

I use the following code to fill a combo box with the installed font names.
I added a button next to it, to refresh the list in case someone added some
new font. I use the following code to build the list. PROBLEM IS, the "new
InstalledFontCollection()" never picks up the new fonts. Only the ones that
were there when my app started.

private void FillComboBoxFontName()
{
comboBoxFontName.Items.Clear();

InstalledFontCollection fonts = new InstalledFontCollection();

foreach(FontFamily family in fonts.Families)
{
comboBoxFontName.Items.Add(family.GetName(0));
}
}