Among the most confusing stories that we have asked .NET Framework customers to understand has been .NET Framework 1.1 support on Windows Server 2003 and 64-bit versions of Windows. I've blogged about this before. Today I get to tell you that we've done right by putting .NET Framework 1.1 servicing releases on Windows Update for 64-bit platforms.
Microsoft releases security updates on the second Tuesday of every month and Windows Update releases non-security updates on the fourth Tuesday of every month. Well, today is the fourth Tuesday in March and we went live with .NET Framework 1.1 Service Pack 1 on Windows Update for supported 64-bit versions of Windows.
None of these are new releases; they are the exact same binaries that are already on Windows Update for .NET Framework 1.1 running on 32-bit Windows operating systems and have always been available for supported 64-bit Windows operating systems on Download Center. What's new is that now if you have .NET Framework 1.1 installed on your x64 or supported Itanium version of Windows then you can keep that .NET Framework 1.1 installation up-to-date using Windows Update, SUS, and WSUS.
It should be noted that there do exist performance issues running .NET Framework 1.1 on Itanium-based systems (here). There is also a known compatibility issue between ASP.NET 1.1 (a component of the .NET Framework 1.1) and IIS 6.0 on 64-bit versions of Windows (here). These are known issues and the current announcement does nothing to mitigate these concerns. Rather, we assume that if you have the .NET Framework 1.1 on a 64-bit Windows system then you have already evaluated and addressed these concerns for your environment.
The supported operating systems are the following: