The European Commission on June 25, 2026, declared that Amazon Web Services and Microsoft Azure should be designated as gatekeepers under the Digital Markets Act. The preliminary finding—while not yet final—threatens to dismantle the proprietary fortresses that have locked businesses into the two largest cloud platforms for years.

For Windows shops running Azure Arc, Active Directory, and Windows Server workloads, the implications are immediate and profound. The DMA is designed to force structural changes in digital markets where a few platforms act as gatekeepers for business users to reach end customers. Now, cloud infrastructure is officially in the crosshairs.

The DMA’s journey to the cloud

The Digital Markets Act took full effect in May 2023. The European Commission initially designated Alphabet, Amazon, Apple, ByteDance, Meta, and Microsoft as gatekeepers for core platform services like search, social networking, and operating systems. Cloud computing—despite its criticality to Europe’s digital economy—was conspicuously absent from that first round. Smaller cloud providers and their trade bodies pushed back immediately, arguing that the IaaS and PaaS layers had become equally concentrated and anticompetitive.

The Commission responded by launching a cloud-specific market investigation in 2024. Data egress fees, contractual restrictions, and technical lock-in mechanisms were top of the agenda. Regulators combed through licensing terms, interoperability APIs, and market share trends. By early 2026, the direction of travel was clear: the EU was nearing a conclusion that AWS and Azure, and possibly Google Cloud, qualified as gatekeepers.

The gatekeeper criteria, translated for cloud

Under the DMA, a company providing a core platform service is designated a gatekeeper if it meets three thresholds:

  • It has a significant impact on the internal market, typically measured by revenue or market capitalization.
  • It provides a core platform service that serves as an important gateway for business users to reach end users.
  • It holds an entrenched and durable market position, or it is foreseeable that it will.

Cloud infrastructure and platform services check every box. In the fourth quarter of 2025, Synergy Research Group reported AWS with 31% market share, Azure with 24%, and Google Cloud with 12%. Together, the trio commands 67% of global cloud spend. For European businesses, switching providers is often prohibitively expensive and technically complex, especially once workloads become dependent on proprietary services like Azure Functions or AWS DynamoDB.

What designation would mean in practice

Gatekeeper designation comes with a list of interoperable obligations. The key ones for cloud:

  • Ban on anti-steering: Providers cannot prevent business users from offering the same service through other cloud providers or on their own infrastructure under different conditions.
  • Data portability: Business users must be able to port their data seamlessly to another provider, and the gatekeeper must provide continuous, real-time access to that data.
  • Interoperability: Gatekeepers must provide free and effective data portability tools and ensure functional equivalence when users interact with third-party services.
  • No self-preferencing: Gatekeepers cannot rank their own cloud services or products more favorably than those of rivals.
  • Mandatory API access: Other cloud providers must be given access to the same operating-system-level APIs and cloud management infrastructure that the gatekeeper uses internally.

Translated to the cloud, this means AWS and Azure would be forced to offer straightforward, automated paths for customers to move virtual machines, databases, and container workloads to competitors. Egress fees—long a revenue generator and a barrier to exit—would be banned. Proprietary management consoles and command-line tools would need open, documented APIs that third parties could integrate without restrictions.

For Microsoft specifically, the DMA scrutiny dovetails with a parallel antitrust complaint settled by CISPE in 2024 over Windows Server licensing. The complaint accused Microsoft of using its dominant desktop OS to steer users toward Azure by charging significantly more to run Windows Server on rival clouds. Under the DMA, such pricing tactics could be deemed illegal self-preferencing. The Azure Hybrid Benefit—whereby customers can bring their existing Windows Server licenses to Azure at a discount—might need to be extended to Google Cloud, AWS, and on-premises environments at equivalent rates.

The Windows-Azure lock-in under fire

No ecosystem illustrates cloud lock-in quite like the Microsoft stack. Windows Server Active Directory, Azure AD, Intune, and Microsoft 365 are deeply intertwined. For millions of IT admins, the path of least resistance is Azure, where hybrid management tools like Azure Arc and Azure Stack HCI promise a unified control plane. But that unity comes at a cost: leaving Azure means losing that seamless management layer, and with it, single-pane-of-glass visibility and policy enforcement.

The DMA would require Microsoft to publish the same APIs that Arc uses internally. Competitors could then build management portals that speak to Azure-hosted and on-premises Windows Servers on equal terms. Similarly, identity data in Azure AD would need to be exportable in a structured, machine-readable format, allowing a business to migrate users and conditional-access policies to a third-party identity provider without starting from scratch.

Data gravity compounds the lock-in. Once a company’s SQL Server databases, SharePoint Online documents, and Power BI datasets reside in Azure, the cost and complexity of moving to another cloud become astronomical. The DMA’s data portability mandate could force Microsoft to contribute to open-source standards for these workloads, similar to how the Windows NT kernel sparked Samba in the 1990s.

AWS under the microscope

Amazon’s lock-in is different but equally powerful. AWS’s vast array of services—over 200 at last count—creates a web of interdependencies. A customer using S3 for storage, DynamoDB for NoSQL, Lambda for serverless, and CloudFormation for infrastructure-as-code faces a daunting rewrite if they ever try to leave. AWS has historically treated proprietary APIs as competitive moats.

Under the DMA, AWS would likely be required to:

  • Support and contribute to open API specifications for its core services.
  • Offer data-transfer tools that are continuously maintained and free, akin to a “self-service divorce” button for each service.
  • Disclose any contractual clauses that hinder switching, such as minimum commitment periods that auto-renew without explicit consent.

One open question is whether the Commission will also target “cloud credits” that startups receive in exchange for long‑term spend commitments. These programs, while marketed as free-tier or startup‑friendly, can quietly build lock‑in from Day 1.

Industry reactions: hope and backlash

CISPE, the trade body representing European cloud infrastructure providers, called the preliminary finding “a victory for digital sovereignty.” Members like OVHcloud, Scaleway, and IONOS have long argued that hyperscaler practices stifle European innovation. “This is not about punishing success,” CISPE Secretary General Francisco Mingorance said at a press conference. “It is about giving European businesses the freedom to choose, mix, and switch cloud services without unfair barriers.”

Hyperscalers, predictably, pushed back. AWS stated it “will continue to work constructively with the Commission,” while stressing that “the cloud market is already fiercely competitive and customers have multiple tools to avoid lock-in.” Microsoft’s statement acknowledged the importance of competition but warned that “overly rigid interoperability mandates could slow the pace of innovation and weaken security postures for critical infrastructure.”

Enterprise customers watched from the sidelines, many of them privately rooting for the EU. A CIO at a large German manufacturer, speaking on condition of anonymity, said, “Every year our cloud bill grows by 20%, and every year leaving feels less possible. If the DMA forces them to open up, maybe we can finally negotiate on equal footing.”

The timeline and the stick

The June 25 preliminary conclusion triggers a formal comment period of up to eight weeks. Following that, the Commission will analyse submissions and issue a final designation decision, likely in early 2027. Once designated, AWS and Azure would have six months to comply. Non‑compliance could result in fines of up to 10% of global annual turnover, a sum that in AWS’s case alone could exceed $11 billion.

Both companies are expected to lobby intensely. They may offer voluntary “efficiency packages”—pre‑announced changes that partially address the EU’s concerns—in hopes of softening the final obligations. But the DMA is structured to prevent such eleventh‑hour concessions from derailing a designation.

What it means for Windows enthusiasts and IT pros

For the Windows community, this regulatory shift could be as transformative as the breakup of the PC‑OS monopoly was. A multi‑cloud Windows Server world would allow admins to run Active Directory, SQL Server, and .NET applications on any cloud with full support and predictable licensing. The “Windows Best on Azure” mantra—implicit or explicit—would become a thing of the past.

Hybrid work and device management could also see change. Intune and Azure Virtual Desktop (AVD) would need to interoperate with third‑party clouds, giving organizations more freedom to deploy Windows 11 or Windows 365 Cloud PCs on non‑Azure infrastructure while still managing them centrally.

Ultimately, the EU’s move marks the end of the hyper‑scale cloud’s “walled garden” era. Lock‑in, once a quiet profit engine, is now a regulatory liability. The coming months will determine just how far the Commission is willing to go to ensure that the cloud becomes a utility—open, contestable, and truly competitive.