The .Net framework can be installed on the following configuration:
Supported Operating Systems: Windows 2000; Windows 98; Windows 98 Second Edition; Windows ME; Windows NT; Windows Server 2003 Service Pack 1 for Itanium-based Systems; Windows Server 2003 x64 editions; Windows Vista Business; Windows Vista Enterprise; Windows Vista Home Basic; Windows Vista Home Premium; Windows Vista Starter; Windows Vista Ultimate; Windows XP; Windows XP Professional x64 Edition
Microsoft Windows NT 4.0 requires Service Pack 6a.
Important: Make sure you have the latest service pack and critical updates for the version of Windows that you are running. To find recent security updates, visit Windows Update.
You must also be running Microsoft Internet Explorer 5.01 or later for all installations of the .NET Framework. Install Internet Explorer 6.0 Service Pack 1.