Error codes

0x800f0907

The .NET Framework 3.5 installation failed

What it means

Windows tried to add .NET 3.5 and could not reach the files it needs, because the source is blocked or no longer available.

Common causes

• Windows Update is set to a WSUS server without the .NET payload
• No internet access during the install
• A group policy that points to a source path that no longer exists

How to fix it

1. Run the Windows Update troubleshooter: Settings > System > Troubleshoot > Other troubleshooters > Windows Update.
2. Install it offline: mount a Windows ISO, then run dism /online /enable-feature /featurename:NetFx3 /All /Source:D:\sources\sxs /LimitAccess with D: as the mounted ISO.
3. If you are on a work PC, ask IT whether the WSUS server offers the .NET 3.5 payload at all.