Vanguard requires Secure Boot + TPM 2.0 when running on UEFI
Enter your BIOS/UEFI and make sure:
Secure Boot is Enabled
TPM 2.0 is Enabled (sometimes called "PTT" on Intel, "fTPM" on AMD)
Double-check Core Isolation / Memory Integrity
Powershell command also use this again: bcdedit /set hypervisorlaunchtype off
Then go to Windows Features (OptionalFeatures.exe) and turn OFF:
Hyper-V
Windows Hypervisor Platform
Virtual Machine Platform
Windows Subsystem for Linux
If above doesn’t fix it, check BIOS:
Intel Virtualization (VT-x / VT-d) Try toggling OFF and test
Sometimes Vanguard conflicts if VT-d is enabled