If I have a button with &Next as the text, the N-accelerator key does not appear until I press Alt. Why

This behavior has nothing to do with .Net and is expected Windows behavior beginning with Win2000. Windows will only show accelerator keys after the alt is pressed. There is a control panel setting that you can use to change this behavior. Look on the Effects tab under Control Panel|Display to see a checkbox labeled ‘Hide keyboard navigation indicators until I use the Alt key’.