.NET Framework 1.1

For developers, .NET Framework 1.1 makes it easy to rapidly create powerful software that maximizes performance, scalability, opportunities for integration, reliability, security, and the end-user experience, while minimizing the costs of deployment and management. The .NET Framework 1.1 SDK runs on Windows Server 2003, Microsoft Windows 2000 (Service Pack 2 recommended), and Windows XP Professional and Home Edition.

Download .NET Framework 1.1

Also,

Microsoft .NET Framework 1.1 Redistributable