I've been running Twilight of the arnor fine for quite a while until I realised there was a .91 and 9.96 patches I hadnt installed.
So I updated to the latest version in stardock central and went to run the game and got an error message:

Deleting the twilight folder and reinstalling off the CD without an uninstall reproduces the error despite not doing an update.
Uninstalling then reinstalling the game off my CD fixes this but as soon as I try to update to the latest it breaks and I get the same issue.
This is under Vista business edition x64. I have the game installed on ym laptop too and it works perfectly fine there on the other hand (Vista Basic 32bit).
I also tried downloading the archive from stardock central and applying it which made no difference either.
Also, when I update to the latest version I get no icon on the maine xecutable file, but this is not the case on my laptop where it works fine.