I downloaded and installed the PA trial, on the license key screen I click "evaluate" since I haven't bought it and don't have a license key, but then it just shuts down saying I need a valid license key.
Hey Xander - just to be sure you're looking under *View* Extensions rather than Edit Extensions (happens to me all the time).
And Ken, I think it sounds like you might have something blocking access to the registry? Make sure your running with admin privileges, and not running anything that like a spyware blocker etc...
Also, both of you should make sure you're not running Vegas when you're installing.
From that error it looks like a corrupt installation. Production Assistant is trying to read it's settings file and could not find it (which in itself says the install went bad) so it tries to recover by creating one and the create is failing! (probably because the folder doesn't exist which is why it gave the "Could not find a part of the path" error)
Look to see if this setting file exists:
C:\Documents and Settings\rread\Application Data\Sony\Production Assistant\1.0\ProductionAssistant.settings
I'm guessing that the path doesn't even exist.
I would uninstall and re-install Production Assistant and it should clear this up.