VirtualBox: Ubuntu instance fails to start with error

I get the below error when trying to start up my Ubuntu instance on VB in my Windows 10 env.

VMMR0_DO_NEM_INIT_VM failed: VERR_NEM_MISSING_KERNEL_API_2 (VERR_NEM_MISSING_KERNEL_API_2). VT-x is not available (VERR_VMX_NO_VMX).

Result Code: E_FAIL (0x80004005) Component: ConsoleWrap Interface: IConsole {872da645-4a9b-1727-bee2-5585105b9eed}

From googling, ive turned off Virtualisation in my laptop but still get this error, any tips?

Turning Virtualisation off is not the answer here. That's what the VT-x is not available error you are getting there is complaining about.

Since there isn't one specific way to fix this, aside from just having the right configuration. I would suggest you go through this with a systematic approach:

• Uninstall VirtualBox.
• Turn off Hyper-V if it is enabled. While the two can co-exist, you will get much better performance from VirtualBox if Hyper-V is disabled.
  • You can turn off Hyper-V from the Turn Windows features on and off settings menu.
• Enabled VT-x (Virtualisation) in your BIOS.
• Reinstall VirtualBox.
• Reinstall your desired guest OS.