How can I remove an item from the New context menu?

Identify the file extension for the context menu item, for example obd for Microsoft Office Binder (if you are unsure of the extension just create a document of the type then check the extension)

Start the registry editor (Regedit.exe)

Move to HKEY_CLASSES_ROOT., e.g.HKEY_CLASSES_ROOT.obd

Delete or rename the ShellNew key. It may not always be at the root of the key, for example to disable .obd I had to goto HKEY_CLASSES_ROOT.obdOffice.Binder.9ShellNew.

Close the registry editor

The context item should no longer be displayed