I recently installed morrowind on my laptop (vista) and it runs just fine. so when i installed tribunal and rested in a bed and the darkrotherhood guy came to attack me i got a message saying that his darkbrotherhood armor and admantanium weapon mesh failed or something like that so i clicked yes and continued so he was just kind of a yellow blob. i killed him and then continued the quest and i found out that every single thing that involves tribunal turned into a yellow blob and it caused alot of crashing. so could someone please help me!
I remember that some folks had to do some manual copying to get the Expansions installed in Vista. Check the pinned Vista Problems thread. I'll do the same and let you know if I find anything.
Edit: Didn't see what I thought I remembered....reinstall Tribunal. Make sure you are and administrator first.