I installed 6.1x/6.2 on Windows Server 2008 x64. By default, the "Context Menu Entry" option is selected during install. However, when I right-click a .txt file in an Explorer window, I don't see the "Edit with Notepad++" menu.
I also notice that the .txt file type is not associated with Notepad++ by default. After I manually added this association in the "Settings > Preferences", I can see Notepad++ appeared in the "Open with..." menu, but I still don't see the "Edit with Ntepad++" menu.