: Starting with Windows 11 version 26H1 , Microsoft has moved .NET 3.5 from being a built-in optional component to a standalone setup. Windows 10 and older versions of Windows 11 are not affected by this change. Why You Might Need the Offline Installer
If the GUI installer still tries to go online, use DISM pointing to local source:
Once you have the dotnetfx35.exe file, follow these steps: .net 3.5 sp1 offline installer
Windows installation media (ISO or USB) available for the machine you're working on? AI can make mistakes, so double-check responses Copy Creating a public link... You can now share this thread with others Good response Bad response 14 sites Offline Installation of Framework .NET 3.5 But for security reasons, the device is disconnected from the internet. This article describes three possible solutions. Keysight Knowledge Center Offline Installation of Framework .NET 3.5 Option 1): a) Press the "Windows Logo" + "R" keys on the keyboard. b) Enter "appwiz. cpl" in the "Run" command field and press "EN... Keysight Knowledge Center How do I install the .NET Framework 3.5? - Microsoft Q&A Oct 24, 2024 —
Integrating into automated deployment scripts for multiple computers. : Starting with Windows 11 version 26H1 ,
The file is named: dotnetfx35.exe (approx. 231 MB)
⚠️ Be careful – that same page also lists a smaller “bootstrapper” (~3 MB). Make sure you download the 200+ MB file. AI can make mistakes, so double-check responses Copy
If you are trying to run legacy enterprise software or older applications on a modern Windows machine, you have likely encountered the dreaded "requires .NET Framework 3.5" error. While Windows 10 and 11 have moved on to newer versions, many essential business apps still rely on the 3.5 framework (which includes SP1).
Note: For Windows 10/11, the "offline installer" frequently refers to using the Windows ISO/USB installation media via DISM command, rather than the old dotnetfx35.exe executable, which may not function properly on modern OS versions.
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