This update combines the features and fixes of two previous updates:

EAX 4.0 ADVANCED HD Driver Patch Update for Sound Blaster Audigy 2 and Audigy 2 ZS (released on 29 March 2004)
EAX 4.0 ADVANCED HD Driver Update for Creative Sound Blaster Audigy 2/Audigy 2 ZS (released on 19 November 2003)
In addition, this update includes a new fix for your Creative Sound Blaster Audigy 2 or Audigy 2 ZS series audio card. Note that this fix is not critical so you can choose not to install this update.