In my case, I had installed Dreamweaver CS3 but had never actually run it. So
in the registry, the Common folder didn't exist. What I did was went into
Dreamweaver 8 and "removed" all the site definitions. Then launched Dreamweaver
CS3. After that Fireworks launched fine. It is a bit disturbing that it was
this difficult to find the answer to this problem

I'm having the same

http://www.graphicseo.com