According to an in-depth investigation by Windows Latest,The Windows 11 monthly cumulative update size has expanded from approximately 300MB in 2024 to 5GB in 2026, and is closer to 9GB after decompression.The AI ​​function did contribute to some of the increase, but the design of the update mechanism itself is the fundamental reason for the continued expansion in volume.

AI Components: Where does the 3GB increase come from?

The cumulative update in May 2025 is a key turning point. The size of the update package in that month increased sharply from about 1.3GB to 4.4GB, and the decompressed size jumped from 6.5GB to nearly 9GB.

WindowsLatest unpacking analysis found that the increase mainly comes from dozens of MSIX components that did not exist before, all related to semantic search and local AI reasoning. This increase of about 3GB can basically be attributed to the AI ​​component.

A key detail here is that these AI components were originally designed for Copilot+ PCs only, and as support expanded to Intel and AMD platforms, more versions were crammed into the same update package.

The applicability check logic of Windows Update will detect the hardware configuration before downloading and only pull the parts actually needed by the system. Tested on a virtual machine without NPU, only about 1.7GB of the 4GB+ directory package was actually downloaded, and the semantic search component was not pulled.

In other words, AI components are packaged in updates, but a large number of users' computers will not have them installed at all.

Technically, these AI models and semantic search components can be distributed separately through the Microsoft Store or on-demand downloads, decoupled from monthly cumulative updates, which Microsoft has not yet done.

Cumulative update mechanism: the real source of volume expansion

Windows 11 uses the latest cumulative update (LCU) model, and monthly security updates contain the fixes of the month as well as all historical fixes. Even if your computer only needs a minor patch, the update package still carries the complete set of changes required to upgrade any system to that version.

This model is clean from a reliability perspective, and installing the latest updates ensures the system is fully updated, even if previous updates were skipped. But the side effect is that the update package will only get bigger, never shrink.

Microsoft has introduced checkpoint cumulative updates in Windows 11 24H2 in an attempt to alleviate this problem. The idea is to establish a new baseline regularly, and subsequent monthly updates only contain changes since the last checkpoint, thus reducing the size.

After the first checkpoint was established in September 2024, the updates up to April 2025 did maintain a relatively small size. However, the update volume tripled in May 2025, and no new checkpoints have been established for more than a year since then. The volume optimization promised by Microsoft is quietly failing.

Enterprise side: Costs skyrocketed 4 times

For home users, the actual download size is much smaller than the directory package size. Most people will not notice the 4-5GB figure, but the enterprise environment does not have this flexibility.

WSUS downloads full cumulative updates every month, Configuration Manager distributes the full package to each distribution point, and the offline service tool injects the full MSU package into the system image. Every scenario requires the full package, even if a single terminal only uses a small part of it.

Windows Latest estimates that the annual update storage cost per distribution point per architecture has soared from approximately 11GB in 2024 to 52GB in 2026, an increase of more than 4 times.

An organization with 5 distribution points consumes over 250GB of disk space per schema per year just for update files, and this does not include savings from periodic cleanups.

Comparison with Apple

Incremental macOS updates are usually in the 1-3GB range, with large version jumps appearing larger, mainly because the hardware version is much smaller than Windows.

Apple also does not have a fixed monthly update schedule. Updates are released when they are ready and have greater flexibility in changing packaging methods. Windows prioritizes compatibility, predictability and the ability to deploy in an extremely large combination of hardware and software configurations.

Windows Latest concluded that the reason why Windows Update is large is because it is designed to run in any configuration and in any enterprise scenario. Microsoft has tried to reduce the size as much as possible, but the package itself is still growing.