Our master reference for every credible Windows 12 leak, organized chronologically.
Early 2023: Project Origins
Internal engineering planning reportedly began Q1 2023, roughly 18 months after Windows 11's GA.
Mid-2023: Copilot+ Foundation
The May 2024 Copilot+ PC announcement is now understood as infrastructure preparation — see our NPU requirements analysis.
Early 2025: "Hudson Valley" Surfaces
Multiple partner sources confirmed the codename, describing the modular kernel, AI Runtime Layer, and Secure Enclave 2.0. Full details in our deep dive.
Q1 2025: Canary Build Strings
Independent researchers found ARL and Vanguard icon path references in Canary manifests, corroborating partner-source leaks.
Q1 2025: OEM Certification Activity
Three Tier-1 manufacturers confirmed certification workloads beginning this quarter, consistent with Q4 2025 launch.
Design Leaks: Fluent UI 3
Leaked documents describe Living Mica, the Vanguard icon system, and MDL3 animations — see our design analysis.
Ongoing: Requirements Clarification
Partner documents describe the two-tier requirements system — see our requirements breakdown.
What We're Watching For
Official Microsoft acknowledgment, a public Insider Preview channel opening, and any OEM timeline shifts.