What are you using (Windows 10, 11, or a Server version)? What is the name of the software that requires .NET 1.1?
Last updated: May 2026. Information accurate based on Microsoft Update Catalog archives and MSDN historical documentation. This article is for educational and legacy support purposes only. microsoft net framework 1.1 service pack 1 64-bit download
If one navigates to the official ( catalog.update.microsoft.com ), they can still find the 64-bit service pack, but it is buried. The specific package is typically named: NDP1.1sp1-KB867460-X64.exe What are you using (Windows 10, 11, or a Server version)
Because Microsoft has largely abandoned this download link, many third-party sites offer "dotnet 1.1 sp1 64 bit free download". What are you using (Windows 10
: Run the newly created netfx.msi from your folder to install the updated version.