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Open files with nfty on Windows

Make double-clicking a CookBook, a Set, a picture or a model in File Explorer open it in nfty, or in the nfty viewer on its own. This is a Windows feature: on Linux and macOS the SYSTEM tab is not there.

nfty registers nothing until you ask. Everything it writes is per user (under HKEY_CURRENT_USER), so no administrator rights are needed, and Remove takes back exactly what it wrote.

Choose what opens where

  1. Open Settings (the gear in the status bar) and the SYSTEM tab.

  2. Choose a target for each row:

    Row Files Choices Suggested
    NFTY FILES .cbk .rcp .igt .set .tin .ktn .mnu Off, App, Viewer App
    PICTURES, 3D .png .jpg .jpeg .glb .gltf Off, Viewer Viewer
    METADATA .json Off, Viewer Off

  3. Press Apply. The REGISTRATION chip reads registered, and the line under it says how many file types now open with this copy of nfty.

What the targets do:

  • App opens the file the way a Recent row would: a CookBook in the Explorer, a Set in the Set browser, a .tin behind its passphrase, a Kitchen as the open workspace. A Menu (.mnu) always opens in the viewer, because the app does not edit one.
  • Viewer opens the file in the viewer alone, with no app window behind it, read-only. An archive opens as a gallery; a picture, model or metadata file opens on its own.
  • METADATA starts Off because most .json files are not asset metadata. The viewer shows the ones in a Set's metadata/ or nfty/ folder and says so for any other.

Each double-click starts its own nfty process, so two files open in two windows.

Make nfty the default for pictures, models and JSON

For nfty's own extensions, Apply is enough: no other program claims .cbk or .set, so nfty becomes their default.

For .png, .jpg, .glb, .gltf and .json, Windows does not let any program make itself the default. Since Windows 10 the default is recorded in a per-user UserChoice key protected by a hash that only Windows' own settings can write, so the choice is always yours. Apply adds nfty to those types' Open with list and to Windows' Default apps, and stops there.

To finish:

  1. Press Default apps…. Windows Settings opens on nfty's page.
  2. Pick each type you want nfty to open.

Read the REGISTRATION chip

Chip Means Do
not registered Nothing is registered. Choose targets, then Apply.
not applied You changed a row since the last Apply. Apply.
registered Every chosen type opens with this copy of nfty. Nothing.
needs repair The registration points at another copy of nfty (usually because the app was moved or updated into another folder), or part of it is missing. The line under the chip says which. Press Repair (the Apply button relabels itself).

Take it back

Press Remove. nfty deletes only what it wrote, for your Windows user:

  • a value is deleted only while it still holds what nfty wrote, and a key only once it is empty;
  • another program's default, or an entry another program added since, stays.

nfty keeps a ledger of every key and value it created (under HKEY_CURRENT_USER\Software\nfty), which is how it knows. Apply removes the previous registration the same way before writing the new one.

What gets registered

For reference, or for checking with regedit. All paths are under HKEY_CURRENT_USER\Software.

Key Holds
Classes\nfty.CookBook, nfty.Recipe, nfty.Ingredient, nfty.Set, nfty.Sealed, nfty.Kitchen, nfty.Menu One ProgID per nfty file type: its name, icon and open command.
Classes\nfty.Viewer.Image, nfty.Viewer.Model, nfty.Viewer.Metadata The viewer ProgIDs for pictures, models and JSON.
Classes\<.ext>\OpenWithProgids nfty's entry in each type's Open with list.
Classes\<.ext> (default value) Set only for nfty's own extensions, and only when empty or already nfty's.
nfty\Capabilities nfty's description and file types for Default apps.
RegisteredApplications (value nfty) Points Default apps at those capabilities.
nfty\Associations The ledger Remove reads.

The open commands are:

"<folder>\Nfty.Desktop.exe" "%1"              # App
"<folder>\Nfty.Desktop.exe" --viewer "%1"     # Viewer

The same two forms work from a shortcut or a terminal, with or without any registration.

When something goes wrong

If Windows refuses a read or a write, the card says so in a sentence and nothing half-done is left unrecorded: a failed Apply keeps its ledger, so Remove or Repair can finish the job.