When a file is selected in the Windows 7 Explorer, the contextual menu doesn't show the "New" element:
How to force the "New" menu/submenu to appear even if a file is selected?
This would make the solution from How to create a new text document (TXT) file by a Hotkey? work even if a file has focus.

HKCR\Folderyou see aShellNewkey. I found that if I duplicated this key underHKCR\FileI got anewoption in the context-menu of a file. But it only appears if I am right-clicking a file type that would normally appear in the 'new' context menu - such as a word document. When I clicknewI get a "new" duplicate of the file I right-clicked and it opens in word. So the secret is probably in there if it is possible at all. Will take some research and testing. – Appleoddity Oct 22 '18 at 17:25