This Autodesk Knowledge Base document: Errors during program startup includes a lot of great tips how to find a solution to problems to start AutoCAD 2008 or AutoCAD LT 2008.
In addition to this I can mention that yesterday something happened with my AutoCAD Architectural 2008 and I could not start it no matter what I did. The solution was simple though. All I had to do was to restart the computer.




