Elias sighed. In an age of gigabit fiber, his current environment was an "air-gapped" vault—completely disconnected from the internet for security. The standard "Download and install" button was a useless ghost. He needed the , the holy grail of legacy compatibility.
You download the tool on a machine with internet, transfer the .exe to your 64-bit Windows 10 PC, and run it.
| Error | Solution | |--------|----------| | – Source files not found | Double-check drive letter and that sxs folder exists. | | 0x800f0950 – DISM error | Run sfc /scannow then DISM /Online /Cleanup-Image /RestoreHealth before retrying. | | Installer hangs at 66.7% | Normal behavior – wait up to 10 minutes. | | Group Policy blocks installation | Check Computer Config → Admin Templates → System → Specify settings for optional component installation . | Net Framework 3.5 Offline Installer Windows 10 64 Bit
Once you have the cab file (let’s assume you copied it to C:\temp\netfx3.cab ), follow these steps.
If you have another PC with .NET 3.5 already installed, you can copy the .cab from C:\Windows\WinSxS\ – but this is messy. Best option: ask your IT department or download the Media Creation Tool from Microsoft and create an ISO on a friend’s PC. Elias sighed
Tools like or WinReducer can slipstream .NET 3.5 into a Windows 10 64-bit installation image offline. This is advanced but perfect for deploying many PCs.
Windows tried to go online even though you used /LimitAccess . Solution: Ensure /LimitAccess is included and that your offline source is valid. Also, ensure your Windows image is not a stripped-down “N” or “KN” edition (those lack media features). If so, download the proper Windows 10 64-bit full version. He needed the , the holy grail of legacy compatibility
For Windows 10 64-bit, the is not just a backup plan—it is the recommended solution for system administrators and advanced users.
In this article, we will cover:
Get-WindowsOptionalFeature -Online -FeatureName NetFx3
Example of integrating into an offline image: