If you're running LDPlayer, BlueStacks, MuMu, VirtualBox, or VMware on a fresh Windows 11 24H2 install and everything is stuck, slow, or crashing — this is why.
Microsoft introduced an undocumented change in 24H2 that ties Virtualization-Based Security (VBS) to Windows Hello. Even if you've done everything right — SVM enabled in BIOS, Hyper-V disabled, Memory Integrity off, hypervisorlaunchtype set to off — the Windows hypervisor is still loading silently in the background.
Your emulator can't access AMD-V or VT-x directly. Instead it falls back to NEM, a software emulation layer that runs like garbage. LDPlayer sits at 94% forever. VirtualBox throws "AMD-V is not available." VMware says the host doesn't support virtualization. All lies. Your hardware is fine. Windows is hijacking it.
The smoking gun is in the VirtualBox log:
HM: HMR3Init: Attempting fall back to NEM: AMD-V is not available
That line means the hypervisor intercepted your CPU's virtualization extensions before VirtualBox could touch them.
I burned hours debugging this on a brand new Ryzen 7 7700X + RTX 5060 Ti build. Every troubleshooting guide on the internet was useless. The fix was buried in a Reddit thread from late 2024 and confirmed across multiple Microsoft Q&A posts that were all marked "not answered."
The culprit is a single registry key that doesn't appear in any official Microsoft documentation:
HKLM\SYSTEM\CurrentControlSet\Control\DeviceGuard\Scenarios\WindowsHello\Enabled
Set it to 0. That's the one everyone is missing. But it's not the only thing you need to hit — there are four phases to fully kill VBS on 24H2.
I wrote a PowerShell script that handles all of it: BCD config, the full DeviceGuard registry tree including the hidden WindowsHello key, Windows feature removal, and Group Policy overrides to stop it from coming back after updates.
Grab it here:
https://sevlegend.com/?page=codes&code=Ld-amd&cp=1
After running it and rebooting, msinfo32 should show "Virtualization-based security: Not enabled" and your VBox.log should read "AMD-V is active" instead of that NEM fallback garbage.
Filed under: things Microsoft should have documented but didn't.