I did this steps and works for me to run VirtualBox on Windows 11 even being Windows Insider
1. Run this command on PowerShell with Admistrator perms:
bcdedit /set hypervisorlaunchtype off
2. Open Windows Settings > Update & Security > Windows Security > Device Security and then under Core isolation, selecting Core isolation details. Then Turn off the option "Memory Integrity".
3. Restart Windows and enjoy!
Source: https://forums.virtualbox.org/viewtopic.php?t=103302
