After installation, confirm using:
DISM /Online /Get-FeatureInfo /FeatureName:NetFx3
Or:
Get-WindowsOptionalFeature -Online -FeatureName NetFx3
You should see State : Enabled.
If you cannot use an ISO, go to the official Microsoft Update Catalog and search for “.NET Framework 3.5 cab” plus your Windows version (e.g., “Windows 10 22H2”). Ensure the file is digitally signed by Microsoft. Do not use any site that ends in .com.co or .download.
You likely do not need to "download" the file separately. Instead, you extract it from a Windows installation image: Microsoft-windows-netfx3-ondemand-package.cab Download
Step 1: Place the CAB file in an easy-to-access folder. For this guide, we’ll assume it’s C:\temp\.
Step 2: Rename the file (optional) to something shorter, e.g., netfx3.cab. This reduces typing errors.
Step 3: Open Command Prompt as Administrator.
Step 4: Run the following DISM command:
DISM /Online /Add-Package /PackagePath:C:\temp\netfx3.cab
Step 5: Wait for the process to complete. It will show a progress bar. When done, you’ll see: “The operation completed successfully.”
Step 6: Restart your PC (even if not prompted, it’s good practice).
This is the most robust method, as DISM works even when Windows Features UI fails.
Steps:
Verification: Open PowerShell or CMD and type:
Get-WindowsFeature -Name NET-Framework-Features
Or simply check Control Panel > Programs > Turn Windows features on or off – .NET 3.5 should be checked.
Enable-WindowsOptionalFeature -Online -FeatureName "NetFx3" -All -LimitAccess -Source "C:\temp"
Cause: You inadvertently booted into Windows Recovery Environment (WinRE) or used the wrong DISM environment. Solution: Boot normally into Windows, then run the command. If you are in WinRE, mount your OS partition first or use the Windows installation media directly.