Nested Virtualization on Windows 11: The VBS Conflict Explained

Introduction After upgrading to a modern system with full virtualization support — including VT-x, EPT, IOMMU, TPM 2.0, and Secure Boot — I expected everything to work flawlessly. Instead, I encountered crashes and instability when running nested virtualization scenarios, particularly when attempting to run VMware inside VMware Workstation Pro . At first, I suspected hardware instability, BIOS misconfiguration, or a VMware bug. However, after extensive testing, I discovered the real culprit: Windows Virtualization-Based Security (VBS) . This article covers: How VBS affects desktop hypervisors on modern Windows 11 (24H2/25H2) Why nested virtualization fails under certain configurations Practical solutions for advanced lab environments requiring full VT-x access The Problem: VMware Nested Virtualization Failures The issue surfaced when I upgraded to a 14th generation Intel CPU with hybrid cores (P-cores and E-cores). While VMware Workstation Pro ran perfectly on the host, problems arose