Uru complete chronicles

I bought the boxed set expecting to find 3 disks -
Uru, to D'ni, and path of the shell

To D'ni was missing.
No problem, maybe its on the path of the shell disk.
Installed Uru then Path of the Shell
Still no to D'ni.
Official download link no longer valid.
Finally managed to download from GamersHell
Installed To D'ni which promptly uninstalled Uru and altered the Path of the
Shell launcher to the To D'ni launcher.

Admitted I installed in the wrong order (because I didn't know at the time)

So....

Should there be another disk in the box ?
If not does installing path of the shell install To D'ni anyway (even if its
not at first obvious) ?
(Maybe it does delete the original and then replace it, but then why does
the Uru launch icon disappear?)
Or, would installing them in the correct order next time do the trick?

Phypps