On Windows (especially later versions), the go to great lengths to hide accelerators. Too many mousers wondering why their menus have underlined letters.
To show them temporarily, press & release the <Alt> key.
To show them permanently (Win XP & earlier), - Tools -> Folder Options -> View - then search through that list.
In Windows 7 & 8, go to "Ease of Access Center" -> "Make Keyboard Easier to Use" -> "Underline keyboard shortcuts and access keys".
The Windows 7 & 8 thing works _most_ of the time. XP always (in my experience).