How to Enable "Underlined Letters for Keyboard Navigation" in Vista...
Underlined letters for Alt + hotkey are not displayed under Vista until you actually hit the Alt key.
To change this under Windows XP, all we had to do was right-click the desktop, select "Properties," go to the "Appearance" tab, select "Effects" button, then uncheck "Hide underlined letters for keyboard navigation until I press the Alt key" box.
Under Vista many have noticed that this option is now gone.
Here's how to enable it...
0) Save any work, close unnecessary programs in preparation for logoff. (to restart Explorer.Exe)
1) Click the Start Menu.
2) Type or copy/paste the following:
Reg.Exe ADD "HKEY_CURRENT_USER\Control Panel\Desktop" /v "UserPreferencesMask" /t "REG_BINARY" /d "be3e078012000000"
3) Accept the prompt to overwrite the value.
4) Logoff, then log back into the same account.
Hotkeys will now be underlined, verified by simply right-clicking the Desktop.
TIP: Quicker way to log off, is to simply hit the 'WINdows' key on your keyboard, then type "shutdown -L" followed by the Enter key, into the Start Menu.
Since the Windows Explorer GUI has been redesigned for Windows 7, I can't guarantee that this will work for Windows 7, but wouldn't be surprised if it does. The only did thing we effectively did, was change the beginning of the "UserPreferencesMask" value from "9E" to "BE". So simply open RegEdit then navigate to "HKEY_CURRENT_USER\Control Panel\Desktop" and change only the first two characters before logging off then back in. Unlike other values, Explorer does not appear to overwrite these during logoff/shutdown/restart. If for some reason you are finding that it does, then simply kill the explorer.exe process before changing those values. Then logoff and back on.