Offline install of .NET Framework 3.5 in Windows 10 using DISM

Windows 10 comes with .NET framework 4.5 pre-installed, but many older programs require the older .NET framework v3.5 installed along with 4.5. When you try to run any such app, Windows 10 will prompt you to download and install .NET framework 3.5 from the Internet. However, this will take a lot of time, or (what prompted me to try this) will fail each download attempt. You can save your time, bandwidth and nerves and install .NET Framework 3.5 from the Windows 10 installation media. This method is much faster and here is how to do it:

To install .NET Framework 3.5 in Windows 10, do the following:

Insert your Windows 10 media (DVD or USB), or mount the ISO image.
Open ‘This PC’ in File Explorer and note the drive letter of the installation media you have inserted. Let’s assume it’s disk D:
Now open an elevated command prompt and type the following command:
1. Dism /online /enable-feature /featurename:NetFX3 /All /Source:D:\sources\sxs /LimitAccess
Replace D: with your drive letter for Windows 10 installation media.
You are done! This will install .NET framework 3.5 in Windows 10.