Microsoft warns new Windows 11/10 installs need this Defender update

Windows installation images don’t always ship with the latest Defender protection. To address this issue, Microsoft has released a new security intelligence update (version 1.429.122.0) for Windows 11, Windows 10, and supported Server editions. It’s a small update, but one that matters—especially during a fresh setup.

Microsoft’s new Defender update closes a security gap in fresh installs

If you’ve recently installed Windows, you may have noticed that Defender updates only kick in after setup. That’s because the Defender files in installation images can be weeks—or even months—old. Microsoft says this can briefly expose new systems to known threats.

With this update, Microsoft is making sure OS images come with the latest malware definitions and binaries. According to its documentation, the updated definitions help close this “protection gap” in early boot-up stages. The update includes protection against newer threats like Lumma, an infostealer that’s reportedly affected 394,000 Windows PCs.

Here’s what the updated Defender package includes:

• Defender package version: 1.429.122.0
• Platform version: 4.18.25040.2
• Engine version: 1.1.25040.1
• Security intelligence: 1.429.122.0

The update applies to Windows 11, Windows 10 (Home, Pro, and Enterprise), Windows Server 2022, 2019, and 2016. So if you’re planning to upgrade to Windows 11 soon, especially with new CPU requirements for version 24H2, make sure your install media has these updates.

Worth noting that the latest intelligence version as of now is 1.429.293.0. So while this package helps, you’ll still get newer updates right after setup.

Microsoft also says this update improves performance in some cases. So even if security isn’t your concern, it might be worth updating for that reason alone.