After the editor is launched, open [Help] → [About VOCALOID3 Editor] and see [System Ver] to confirm the current version.
And, if there is a problem that disturbs VOCALOID3 Editor and Tiny VOCALOID3 Editor to launch, please refer to properties of following file(s).
(1) For VOCALOID3 Editor: C:\Program Files\VOCALOID3\VOCALOID3.exe
(2) For Tiny VOCALOID3 Editor: C:\Program Files\VOCALOID3TINY\VOCALOID3TINY.exe
Right click the selected file, and choose [Property] → [Description] to see the version of the product.