Please, make sure to read the ReadMe, and notice there are separate downloads for both 32 and 64-bit.
If you need assistance, login here and submit a support ticket or request for our remote online support.
Enjoy!
Update 1 for Revit Architecture 2013 was released!
You can download it here: http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=20121970&linkID=9273944