Delete obsolete "new" document types.

When one right-click on an empty area of Windows Explorer, there's the
"New" menu. Some stupid shareware applications, which I had installed
just to test then deleted, have registered their document type and
didn't removed them when they were uninstalled.

On Windows XP, I could use Tweak UI to remove unwanted "New" document
types, but there's no Tweak UI for Vista, and since I'm using x64
Vista, I cannot run Tweak UI in compatibility mode for Windows XP. How
am I supposed to remove them, not directly editing the Windows
Registry?

Windows Vista is great, but there are a few things even got worse than
Windows XP : file type managing (associating file extensions with
applications, adding secondary menus and so on), Explorer toolbar
customization (choosing buttons to display), Explorer column
management (choosing columns to display in details view)