If the system doesn't have a "python3.exe" on PATH, then "env python3" will run a registered version, exactly like it currently does. IMO, this is slightly less confusing than the current behavior, which skips searching PATH in this case. We can take it a step further, however. If the launcher can't find the versioned name, then search for "python[w].exe" and determine its version using the approach I outlined above. If it doesn't match the required version, as always the launcher will default to running a registered version.