I tried with Impulse, and I get this:
Windows Add/Remove does not work, because the games are not listed there (probably because they have been installed via stardock).
SDC only shows old versions: wants to downgrade DA to 1.80g.100 (Impulse has updated to 1.80g.103) and does not show newer than TA 1.91.021...
I'm lost at this point.
EDIT: Loaded Stardock again, switched to US-1, then it updated TA to 1.95 (but the exe still is 1.91). Loaded Impulse and there I see a yellow exclamation mark at TA and verification claims: "Twilight of the Arnor is not installed correctly. Please look for an application update"... but the version number seems to be right now.
EDIT2: Found the registry path issue in one of the comments to the patch and corrected the path. Now Impulse performs a new install of ToA; let's see.