Windows 10 comes with .NET 4.5 framework available, but most of the apps require the .NET framework v3.5 installed along with 4.5. These apps will not run unless you will install the required version. This tutorial will show you how to install .NET Framework 3.5 from the Windows 10 installation media. Here are the steps:
To install .NET Framework 3.5 in Windows 10, do the following:
How to Install .Net Framework 3.5 on Windows 10 Offline
1. Double click its ISO image, or insert your Windows 10 DVD or your bootable flash drive with Windows 10.
2. Open “This PC“. In File Explorer, note the drive letter of the installation media you have inserted. In my example, it is disk D:
3. After that, start a Command prompt as Administrator. Type the following command:
Dism /online /enable-feature /featurename:NetFX3 /All /Source:X:\sources\sxs /LimitAccess
Replace X: with your drive letter for Windows 10 installation media.
4. Wait for process to complete.
This will install .NET framework 3.5 in Windows 10.
Checkout this video to illustrate this guide:
Hope something helps you.