Windows 8.1 Deployment .NET Framework 3.5 Installation Method

Windows 8.1 includes the .NET Framework. The .NET Framework 4.5.1 is installed by default during OS installation. If the program requires .Net Framework 3.5 support, the related features will be automatically enabled.
Note:
1. .NET Framework 3.5 also supports building applications based on .Net Framework 2.0/3.0/3.5.
2. Before installing the Windows Language Pack, you need to install .Net Framework 3.5 first.
3. .Net Framework 3.5 no longer provides Windows CardSpace.
First, enable .Net Framework 3.5 on demand. If the program requires .Net Framework 3.5 support, the related functions will be automatically enabled.

Second, the control panel is enabled. Net Framework 3.5
Open the control panel, click "Programs", select "Enable or disable Windows function", select Microsoft .Net Framework 3.5.

Note: Two sub-items apply to developers who need WCF scripts and handler mapping. No need for general users to choose.
The above two installation methods require an Internet connection. If you do not want to use an Internet connection, you can use DISM (Deployment Image Service and Management Tool) to deploy offline. Net Framework 3.5
1. Win+X Select Command Prompt (Admin mode).
2. Load the installation image. In this example, the installation image is loaded to the d drive. The installation source is located at d:\\sources\\sxs. Enter the following command:
DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:d:\\sources\\sxs
/Online Specifies to enable related features in the running operating system
/Enable-Feature /FeatureName:NetFx3 Specifies to enable .Net framework 3.5
/All enable All parent functions of .Net framework 3.5
/LimitAccess Block DISM from Windows Update connection
/Source Specify where you want to enable features