If you simply double-click the .exe, it may still try to download files from Windows Update. To force a true offline installation, use the built-in Deployment Image Servicing and Management (DISM) tool instead.
Step-by-step:
Yes. Microsoft explicitly supports it via the "Windows Features" panel. It runs in a side-by-side (SxS) manner, meaning it does not replace newer versions like .NET 6, 7, or 8. If you simply double-click the
Meaning: The sources\sxs folder in your ISO is corrupt or mismatched with your OS build.
Fix: Download a fresh ISO. Ensure the ISO matches your OS edition (Pro vs. Home) and architecture (x64 vs x86). You cannot use a Windows 10 1809 ISO to install on Windows 11 24H2.
If you are trying to run legacy software or older games on a modern Windows PC, you have likely encountered an error message requesting the .NET Framework 3.5. While Windows 10 and 11 come with newer versions pre-installed (like 4.8), version 3.5 is often missing by default. Install using DISM (no internet required):
Most users instinctively try to download it from Microsoft’s website, only to find a small "web bootstrapper" file that fails because it cannot connect to Windows Update. The solution is the Offline Installer.
This guide covers everything you need to know about downloading the offline installer and installing it without an active internet connection. Wait for the operation to complete (progress bar
This indicates a Secure Boot or BIOS issue.
If you have downloaded the standalone package or if you have a Windows 10/11 Installation USB/DVD handy, you can install it using the Command Prompt. This is the most reliable method that bypasses Windows Update glitches.
Wait for the process to reach 100% and restart your computer.
Absolutely. The sxs folder is not product-key specific. You can copy microsoft-windows-netfx3-ondemand-package.cab to a USB drive and run the DISM command pointing to C:\sxs on your offline machine.