Host Integration Server 2004 SP1 is now available on the Microsoft Download Center.
The download package can be found at the following location.

Microsoft Host Integration Server 2004 Service Pack 1 contains a number of fixes in a single update package. You can use this single package to update any of the following Host Integration Server 2004 editions, including both client and server installations:

  • Developer Edition
  • Standard Edition
  • Enterprise Edition

A list of the bugs that are fixed in this service pack is available in the following knowledge base article.