系统自带.net版本

首先我们可以参照下面的图来得到各Windows系统包括server版的自带.NET Framework的信息，下图只列出了.NET Framework 2.0及其之后的版本。

Which Version of .NET is Built into Windows

下面是比较完整的参考列表 （转自Aaron Stebner’s WebLog）：

• Windows XP Media Center Edition (Windows XP SP1) includes the .NET Framework 1.0 + SP2 as an OS component
• Windows XP Media Center Edition (Windows XP SP2 and higher) includes the .NET Framework 1.0 + SP3 as an OS component.  On Windows XP Media Center Edition, the only way to get the .NET Framework 1.0 SP3 is to install Windows XP SP2 or higher.  There is not a standalone 1.0 SP3 installer for this edition of Windows XP.
• Windows XP Tablet PC Edition (Windows XP SP1) includes the .NET Framework 1.0 + SP2 as an OS component
• Windows XP Tablet PC Edition (Windows XP SP2 and higher) includes the .NET Framework 1.0 + SP3 as an OS component.  On Windows XP Tablet PC Edition, the only way to get the .NET Framework 1.0 SP3 is to install Windows XP SP2 or higher.  There is not a standalone 1.0 SP3 installer for this edition of Windows XP.
• Windows Server 2003 (all x86 editions) includes the .NET Framework 1.1 as an OS component; 64-bit versions of Windows Server 2003 do not include a version of the .NET Framework as an OS component
• Windows Vista (all editions) includes the .NET Framework 2.0 and 3.0 as OS components  3.0 can be added or removed via the Programs and Fatures control panel.
• Windows Vista SP1 (all editions) includes the .NET Framework 2.0 SP1 and 3.0 SP1 as OS components.  3.0 SP1 can be added or removed via the Programs and Features control panel.
• Windows Server 2008 and Windows Server 2008 SP1 (all editions) includes the .NET Framework 2.0 SP1 and 3.0 SP1 as OS components.  The .NET Framework 3.0 SP1 is not installed by default and must be added via the Programs and Features control panel though.
• Windows Server 2008 SP2 (all editions) includes the .NET Framework 2.0 SP2 and 3.0 SP2 as OS components.  The .NET Framework 3.0 SP2 is not installed by default and must be added via the Programs and Features control panel though.
• Windows Server 2008 R2 (all editions) includes the .NET Framework 3.5.1 as an OS component.  This means you will get the .NET Framework 2.0 SP2, 3.0 SP2 and 3.5 SP1 plus a few post 3.5 SP1 bug fixes.  3.0 SP2 and 3.5 SP1 can be added or removed via the Programs and Features control panel.
• Windows 7 (all editions) includes the .NET Framework 3.5.1 as an OS component.  This means you will get the .NET Framework 2.0 SP2, 3.0 SP2 and 3.5 SP1 plus a few post 3.5 SP1 bug fixes.  3.0 SP2 and 3.5 SP1 can be added or removed via the Programs and Features control panel.

Note – for the .NET Framework 2.0, 3.0 and 3.5, you can see a graphical view of the above information in this blog post.

In addition, the .NET Framework shipped with the following versions of Windows but not as truly integrated OS components:

• Windows XP Home and Professional SP1 includes the MSI-based .NET Framework 1.0 + SP2 in the Additional Components folder on the installation CD.  It is not an OS component on this OS.
• Windows XP Home and Professional SP2 includes the MSI-based .NET Framework 1.1 + SP1 in the Additional Components folder on the installation CD.  It is not an OS component on this OS.
• Windows XP Home and Professional SP3 includes the MSI-based .NET Framework 1.1 + SP1 in the Additional Components folder on the installation CD.  It is not an OS component on this OS.
• Windows Server 2003 R2 includes the MSI-based .NET Framework 2.0.  It appears in Add/Remove Windows Components as an OS component, but selecting it simply invokes the MSI-based installer.  The MSI can be repaired and removed using Add/Remove Programs regardless of whether it is installed via the standalone MSI or via the Add/Remove Windows Components UI.