.NET Framework version 1.1 for 64-bit operating systems

Applies To:Windows Server 2003 with SP1
What does the .NET Framework do?
The.NETFramework is a new computing platform designed to simplify application development in the highly distributed
environment of theInternet.The.NETFramework has several main components: thecommon languageruntime, the
.NETFramework class library,and theruntime hosts.Thecommon languageruntimeis thefoundation of the.NETFramework.
It manages codeexecution and provides coreservices such as memory management, thread management,and remote
execution.The.NETFramework class library is a comprehensive, object-oriented collection of reusableclasses thatyou can use
to develop a widerange of applications, including ASP.NETapplications and XML Web services.The.NETFramework also
provides several runtime hosts, including Windows Forms and ASP.NET, which work directly with theruntimeto providea
scalable, server-sideenvironment for managed code.
In the previous release of the 64-bitversions of the Microsoft Windows Server 2003 operating systems and Microsoft
Windows XP Professional x64 Edition operating system the.NETFramework was not supported. In the 64-bitversions of
Windows Server 2003 Service Pack 1 and Windows XP Professional, the.NETFramework is supported.The Microsoft .NET
Framework 1.1 is built into all products in the Windows Server 2003 family except for the 64-bitversions.
The 32-bitversion of .NETFramework 1.1 is supported by 64-bitversions of Windows Server operating systems and can be
installed for 32-bitapplications running on 64-bitversions of Windows operating systems (WOW64).
To install .NETFramework 1.1,visit Windows Updateand select the.NETFramework 1.1 package or see”Microsoft .NET
Framework Version 1.1 Redistributable Package”at the Microsoft Download Center Web siteat
http://go.microsoft.com/fwlink/?LinkId=17153.To install theservice pack,visit Windows Update or see”Microsoft .NET
Framework 1.1 Service Pack 1″at the Microsoft Download Center Web siteat http://go.microsoft.com/fwlink/?LinkId=39058.
Important performance and scalability information for Itanium-based systems
If a 32-bitversion of the.NETFramework is installed on 64-bit Itanium-based systems,applications created for the 32-bit
version of theFramework will bind and run against it.Therefore,applications created with the Microsoft .NETFramework 1.1
run only in a 32-bit process within the WOW64 compatibility environment. Dueto the design of x86 emulation and the
WOW64 subsystem for theItanium processor family applications arerestricted to execution on one processor.
Single processor execution and x86 emulation reducethe performanceand scalability of 32-bit .NETFramework applications
running on Itanium-based systems.Werecommend thatapplications using the.NETFramework 1.1 be used for interactive,
clientapplications.We do not recommend this environment for .NETFramework 1.1 applications that demand high
performance or scalability, such as high-load ASP.NETapplications.Wesuggest thatapplication developers instead evaluate
the.NETFramework 2.0, which includes native 64-bit support for Itanium-based systems, for increased performanceand
scalability.
Who does this feature apply to?
This featureapplies to users with applications written to usethe.NETFramework 1.1 and also to application developers
developing .NETFramework 1.1 applications that will berun on both 64-bitand 32-bit operating systems.