[via Rob Caron’s blog]

This download installs Service Pack 1 for Microsoft® Visual Studio® .NET™ 2003. Fixes in this Service Pack concern stability and security enhancements made in many areas of the product. A comprehensive list of hotfixes requested by customers since the release of Visual Studio® .NET™ 2003 and included in this Service Pack can be found by following the appropriate link under Related Resources on this page.

From: Visual Studio .NET 2003 SP1

You can also download the Visual Studio .NET 2003 SP1 Release Notes.