在 Windows 10、Windows 8.1 和 Windows 8 上安装 .NET Framework 3.5Install the .NET Framework 3.5 on Windows 10, Windows 8.1, and Windows 8

必须安装 .NET Framework 3.5,才能在 Windows 10、Windows 8.1 和 Windows 8 上运行应用。You may need the .NET Framework 3.5 to run an app on Windows 10, Windows 8.1, and Windows 8. 对于旧版 Windows,也可以按照以下说明操作。You can also use these instructions for earlier Windows versions.

下载脱机安装程序Download the offline installer

.NET Framework 3.5 SP1 脱机安装程序可在 .NET Framework 3.5 SP1 下载页上找到,并且适用于 Windows 10 之前的 Windows 版本。The .NET Framework 3.5 SP1 offline installer is available on the .NET Framework 3.5 SP1 Download page and is available for Windows versions prior to Windows 10.

按需安装.NET Framework 3.5Install the .NET Framework 3.5 on Demand

如果尝试运行的应用要求安装 .NET Framework 3.5,则会看到以下配置对话框。You may see the following configuration dialog if you try to run an app that requires the .NET Framework 3.5. 选择“安装此功能” ,启用 .NET Framework 3.5。Choose Install this feature to enable the .NET Framework 3.5. 此选项需要 Internet 连接。This option requires an Internet connection.

.NET Framework 安装对话框的屏幕截图。

为什么我会看到此弹出项?Why am I getting this pop-up?

.NET Framework 是由 Microsoft 创建,用于提供应用程序运行环境。The .NET Framework is created by Microsoft and provides an environment for running applications. 有多种不同版本。There are different versions available. 许多公司都开发使用 .NET Framework 运行的应用程序,并且这些应用都定目标到具体版本。Many companies develop their apps to run using the .NET Framework, and these apps target a specific version. 如果看到此弹出项,表明尝试运行的应用程序需要 .NET Framework 版本 3.5,但未在系统上安装此版本。If you see this pop-up, you're trying to run an application that requires the .NET Framework version 3.5, but that version is not installed on your system.

在控制面板中启用 .NET Framework 3.5Enable the .NET Framework 3.5 in Control Panel

可以通过 Windows 控制面板启用 .NET Framework 3.5。You can enable the .NET Framework 3.5 through the Windows Control Panel. 此选项需要 Internet 连接。This option requires an Internet connection.

  1. 按下键盘上的 Windows 徽标键 Windows 徽标键徽标的屏幕截图Press the Windows key Screenshot of the Windows key logo. 键入“Windows 功能”,然后按 Enter。on your keyboard, type "Windows Features", and press Enter. 随即显示“打开或关闭 Windows 功能”对话框 。The Turn Windows features on or off dialog box appears.

  2. 如果弹出提示,选择“.NET Framework 3.5 (包括 .NET 2.0 和 3.0)” 复选框,选择“确定”,然后重启计算机 。Select the .NET Framework 3.5 (includes .NET 2.0 and 3.0) check box, select OK , and reboot your computer if prompted.

    显示通过控制面板安装 .NET 的屏幕截图。

    无需选择“Windows Communication Foundation (WCF) HTTP 激活” 和“Windows Communication Foundation (WCF) 非 HTTP 激活” 的子项,除非是需要使用此功能的开发者或服务器管理员。You don't need to select the child items for Windows Communication Foundation (WCF) HTTP Activation and Windows Communication Foundation (WCF) Non-HTTP Activation unless you're a developer or server administrator who requires this functionality.

.NET Framework 3.5 安装疑难解答Troubleshoot the installation of the .NET Framework 3.5

安装过程中,你可能会遇到错误 0x800f0906、0x800f0907、0x800f081f 或 0x800F0922,此时请参阅 .NET Framework 3.5 安装错误:0x800f0906、0x800f0907 或 0x800f081f,了解如何解决这些问题。During installation, you may encounter error 0x800f0906, 0x800f0907, 0x800f081f, or 0x800F0922, in which case refer to .NET Framework 3.5 installation error: 0x800f0906, 0x800f0907, or 0x800f081f to see how to resolve these issues.

如果仍无法解决安装问题,或未连接到 Internet,可以尝试使用 Windows 安装介质进行安装。If you still can't resolve your installation issue or you don't have an Internet connection, you can try installing it using your Windows installation media. 有关详细信息,请参阅使用部署映像服务和管理 (DISM) 部署 .NET Framework 3.5For more information, see Deploy .NET Framework 3.5 by using Deployment Image Servicing and Management (DISM). 如果使用的是 Windows 7、Windows 8.1 或最新的 Windows 10 版本,但没有安装媒体,请在此处创建最新的安装媒体:为 Windows 创建安装媒体If you're using Windows 7, Windows 8.1, or the latest Windows 10 version but you don't have the installation media, create an up-to-date installation media here: Create installation media for Windows. 有关 Windows 10 按需功能的附加信息:按需功能Additional information about Windows 10 Features on Demand: Features on Demand.

警告

如果不依赖 Windows 更新作为源来安装 .NET Framework 3.5,则必须确保严格使用来自相同的、对应的 Windows 操作系统版本的源。If you're not relying on Windows Update as the source for installing the .NET Framework 3.5, you must ensure to strictly use sources from the same corresponding Windows operating system version. 使用来自不同 Windows 操作系统版本的源将安装与 .NET Framework 3.5 不匹配的版本,或导致安装失败,使系统处于不受支持和无法提供服务的状态。Using sources from a different Windows operating system version will either install a mismatched version of .NET Framework 3.5 or cause the installation to fail, leaving the system in an unsupported and unserviceable state.