It's not your imagination: Windows installation files are bigger than ever. Over the past decade, the size of Microsoft's ISO downloads has crept upward, and recent releases have crossed the 8 GB mark. The root cause, according to deployment experts, is the growing amount of AI-related code baked into the operating system.

Key facts at a glance

• Windows installation media has roughly doubled in size over the last 10 years, now exceeding 8 GB for some multi-edition ISOs.
• The Media Creation Tool still produces a download close to 6.8 GB, nearly twice the size of the original Windows 10 release.
• Microsoft's official Windows 11 minimum requires 64 GB of system storage, but a clean install of the latest version can consume about 28.2 GB before adding apps or user data.
• Roughly 3 GB of shared AI models are included in cumulative updates for Copilot+ PCs, and these files are downloaded even on machines without an NPU.
• Experts argue Microsoft should move some AI components to the Microsoft Store to avoid bloating Windows Update and monthly cumulative updates.

The steady growth of Windows ISOs

If you have downloaded Windows installation media since the first release of Windows 10 in 2015, you may have noticed a slow but steady climb in file size. What once seemed like a large download has become even larger. A multi-edition ISO for Windows 11 version 25H2, released in July 2026, is more than 8 GB. That is nearly double the size of the original Windows 10 ISO files.

One Windows deployment expert who spent 16 years at Microsoft working on deployment tools has been tracking this growth in detail. Between the initial release of Windows 11 version 24H2 in November 2024 and the latest version 25H2 in July 2026, the installer gained almost 6,000 new folders and more than 20,000 new files. Because 25H2 was delivered as an enablement package for 24H2, they share the same underlying branch. Even so, the size of the installation payload is growing at a rate that makes IT teams nervous.

Why the sudden jump in size?

Windows has always grown over time. Every new feature needs code, and new code needs disk space. But the latest surge is not just the natural result of adding features. It is tied to Microsoft's push to put AI capabilities directly on the PC. Copilot+ PCs include a neural processing unit, or NPU, which is designed to accelerate local AI workloads. Those workloads depend on shared AI models that are stored on the system drive.

Microsoft has been shipping these AI models as part of the monthly cumulative update packages. As a result, every Windows 11 system receives the bits, even if it does not have an NPU and cannot use them. The installer simply ignores them on unsupported hardware, but the download still arrives over the network and consumes disk space while it is being processed.

Copilot+ PCs and the cost of local AI

Local AI is central to Microsoft's strategy. Instead of sending every request to the cloud, Windows can run small language models and image models directly on the device. This approach offers privacy and performance benefits, but it also adds a significant storage requirement. In the current release, there are dozens of WindowsWorkload related files dedicated to AI processing. These files, together with other AI components, account for about 3 GB of the installation payload.

This is a problem for people with smaller drives. The official hardware requirements for Windows 11 allow a minimum of 64 GB of system storage. However, a clean installation of the latest release, with updates applied, can consume 28.2 GB in a virtual machine that starts with a 64 GB virtual drive. That leaves little room for applications, user files, and future updates. It is hard to imagine using a machine with that little storage for anything beyond basic browsing and document editing.

Bloat or evolution?

People have been calling Microsoft software bloated since the days of MS-DOS. The Windows XP review that described the operating system as a "monstrous, bloated brute" was written more than two decades ago. At the time, it needed two gigabytes of hard disk space, and reviewers were shocked by the requirement. Today, that sounds like a tiny amount of data.

The difference is that hardware improvements used to keep up with software growth. When Windows XP needed 2 GB, hard drives were already moving past 40 GB. When Windows 10 needed between 16 GB and 20 GB, 256 GB SSDs were common on budget laptops. Now the supply chain is less predictable. Memory and storage prices have risen sharply, and that trend is expected to continue for years. The "just add more hardware" strategy is becoming less practical, especially for budget PCs that ship with 64 GB eMMC storage.

Large updates hurt IT teams

For corporate IT professionals, the growing size of Windows installation files is a serious concern. Deploying Windows to hundreds or thousands of computers over a network requires bandwidth and time. If each device has to download 6.8 GB or more from an internal server, that also requires storage space on the deployment server. The monthly cumulative updates are just as problematic. They have grown significantly because of the AI payload, and they are delivered through Windows Update to every machine.

Microsoft could ease the burden by shifting some AI components to the Microsoft Store. The Store already handles several system components in Windows 11. Items such as the Photos app, the Snipping Tool, and some more advanced features are delivered as Store apps, which do not require a restart and are updated only when the app is in use. If Microsoft applied the same approach to AI models, machines without an NPU would not need to download them at all. Machines with an NPU could update the models on a schedule that does not interfere with work.

Why 64 GB is no longer enough

Microsoft's 64 GB minimum for Windows 11 is a vestige of an earlier era. Even after installation, the operating system continues to grow with updates, optional features, and apps. A machine with 64 GB of storage may show a warning after a few months or become completely full if the user tries to install substantial programs. The AI push only makes this worse.

Deployment professionals now recommend at least 128 GB of system storage for a basic Windows PC. For developers, designers, and anyone who works with local AI models, a terabyte or more is becoming the practical standard. This is not only about the operating system payload. It is also about headroom for page files, hibernation files, recovery partitions, and the temporary files created during major updates.

What users and IT teams can do

For users with smaller drives, there are a few steps that can help. Windows includes a cleanup tool that can remove previous installations and temporary files after a feature update. Storage Sense can automatically clear caches and old downloads. Users can also move large folders such as Documents, Pictures, and Videos to a secondary drive or a microSD card. For machines with a 64 GB drive, however, these measures are only temporary. The long-term solution is to replace the drive with a larger one or choose a machine with at least 128 GB of storage.

Businesses have additional options. They can use Windows Update for Business to defer non-essential updates, or they can use delivery optimization to share downloads across the network. They can also use tools to strip out unnecessary language packs and Windows components from installation images. But if Microsoft continues to put AI models in the cumulative update pipeline, these measures will only do so much.

What happens next

The rise of local AI in Windows is unlikely to slow down. Microsoft has been adding AI features to every new release, and the trend is clear. As AI models become more capable, they will likely get larger before they get smaller. The challenge for Microsoft is to deliver these models without overwhelming the monthly update pipeline or the limited storage found on budget devices.

For now, the best advice is to plan for more storage than you think you need. A machine with 64 GB of storage may have been acceptable a few years ago, but it is no longer a realistic choice for Windows 11. The AI-powered features that Microsoft is pushing forward require space, and that space has to come from somewhere. Users with larger drives may not notice the growing file sizes, but anyone trying to run Windows 11 on a small, budget-friendly PC will feel the pressure sooner rather than later.

Source: ZDNET News