Over time, Windows updates have become increasingly comprehensive and much larger in file size. The monthly cumulative updates that Microsoft releases every Patch Tuesday now regularly exceed 4 to 5 GB each, and in some cases even reach 9 GB. Just two years ago, many Windows updates were only 300 to 500 MB in size.
Windows Latest has investigated the reasons behind this trend. According to their findings, several factors play a role in the ever-increasing size of Windows updates.
Reason 1: AI features
These days, Microsoft includes not only changes to basic Windows functions in every update, but also numerous AI features. The problem is that not every PC actually uses all of these AI features.
In reality, a freshly downloaded update from the Windows Update catalog may initially be 4 GB in size. Once the installation has started, the system checks how much of it is actually needed and may ultimately end up using only 1 to 2 GB of the update. In this case, you’ve downloaded way more data than necessary for no benefit.
This system was introduced with the first Copilot+ PCs in 2024 and has been part of the process ever since. Microsoft could instead offer separate updates for AI PCs, but has so far chosen not to do so.
Reason 2: Cumulative delivery
Microsoft hasn’t been delivering small, isolated patches for some time now, opting instead for cumulative updates. The monthly security update therefore contains not only the latest patches, but all previous ones as well, so that a missed update is never completely skipped and doesn’t result in any major consequences.
Unfortunately, the downside of this is ballooning update sizes. With Windows 11 24H2, Microsoft introduced so-called checkpoints, which the system recognizes and only installs patches up to that point. However, the intervals between checkpoints became increasingly longer, meaning they ultimately stopped serving their intended purpose. For comparison, the April 2025 cumulative update was 1,287 MB in size while the one from May 2025 was 4,369 MB.
It’s reportedly difficult for Microsoft to offer specific updates for specific systems, adapting them to every specific situation. Consequently, Windows updates for WSUS are also cumulative. Due to the current storage crisis, enterprises are facing their own data management challenges, and large updates are an additional burden for them.
Reason 3: Monthly frequency
Unlike Apple, which as a company adopts a strategy of only delivering updates when they’re ready, Microsoft sticks to a fixed monthly schedule. Even so, Apple’s updates are somehow still smaller on the whole (excluding major releases).
While Windows’ monthly update cycle has its advantages and makes patches more predictable, it can also make them inflexible. The fixed schedule also forces developers to plan changes in clear cycles and, in some cases, pack several changes into a single update rather than opting for smaller, dynamic updates.
How to check what your PC is downloading during an update
Under Settings > Windows Update > Advanced options > Delivery optimization > Activity monitor, you can see download statistics and an overview of how much data comes from Microsoft, from local network partners, and from the cache server.
PC Welt / Foundry
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