Where can I download the current AC Installer?
From Drunkapedia
A current installer can be downloaded from Turbine here:
http://ac.turbine.com/index.php?page_id=381
The installer exe is at the bottom of the page. You can no longer install AC from the original or expansion CDs.
Once installed, connect and the launcher will automatically update and your client will update and then you'll be able to play.