By default, Windows 10/11 does not install .NET 3.5. When you enable it via Turn Windows features on or off, Windows tries to fetch files from Windows Update. If your PC lacks internet access (or WSUS doesn’t have the feature), the installation fails.
Using this CAB file allows you to install .NET 3.5 offline or in air-gapped environments.
Once you have the .cab file, you have two primary methods to install it: using DISM (Deployment Imaging Servicing and Management) – the recommended approach for all users, or using PowerShell.
If you have extracted the CAB into C:\windows\sources\sxs\, you can also go to: Download Microsoft-windows-netfx3-ondemand-package.cab
Method A: From a Windows ISO (recommended for safety)
Method B: Via DISM from Windows Update (if online)
LOGIN
Registrarse
DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sources\sxs
(Replace D: with your ISO mount point)
Method C: Manually from another same-version, same-arch PC
Crucially, never download CAB files from random forums or file-sharing sites.
You have two safe sources:
⚠️ Unsigned or mismatched CAB files can corrupt your .NET installation or cause security issues. Always verify the digital signature (right-click → Properties → Digital Signatures).
Windows Installation Media (ISO or USB)
If you have a Windows installation USB drive or an ISO file mounted, the CAB file is already present in the \sources\sxs\ folder. Look for a file named microsoft-windows-netfx3-ondemand-package.cab. This is the safest, fastest method because the file is directly from Microsoft and digitally signed.
Volume Licensing Service Center (VLSC) For enterprise IT administrators, the CAB file is included in the original ISO images available from VLSC or the Microsoft 365 Admin Center. By default, Windows 10/11 does not install