Dan,
I found out that Ecotect 2010 that was first posted to the Assistance Program required License Manager which was not part of the download. Check the program software downloads and you'll see that they pulled 2010 and substituted 2009. I told Adsk that although the program is terrific, that I had no interest in learning "old software". My interest lies in Revit and seeing how the Revit 2009 and 2010 model interacts with Ecotect 2010. One of Ecotect 2010's noted improvements is interaction with Revit. So, in my case, wouldn't want to spend one minute lookiing at old software (Ecotect 2009).
You mentioned receiving an error. Recommend doublechecking to see if you downloaded 2009 or 2010 product. If it's the 2010, you won't be able to get it running (without License Mgr which was not part of the download). If it's 2009... I can't help you, but I assume you should be able to get it going.
Tom