The Pro Tools|HD 7.3.1 cs3 update can be installed over Pro Tools|HD 7.3 or Pro
Tools|HD 7.3.1 and includes all updates that were previously made available in
the 7.3.1, 7.3.1cs1 and 7.3.1cs2 releases. The latest release is available as a
free download for registered Pro Tools|HD 7.3 users (www.digidesign.com/support).