I am the administrator and UAC is in the full position. Installing from scratch, and NOT running the installers as admin, produced both programs working correctly.
I don't think that was necessary, because Convoi doesn't use it and Vignette only uses one entry to store the path to Convoi.
I've just removed Convoi and Vignette from my Win 10 partition and gone through the Registry removing all references to both programs.
