Fail to start XP VM

[Achillone]

SOLVED THANKYOU

I've been using a virtual Windows XP machine since years, but today I cannot start it anymore.
The message I get is:

"Apertura di una sessione per la Macchina Virtuale XP non riuscita.
Not in a hypervisor partition (HVP=0) (VERR_NEM_NOT_AVAILABLE).
VT-x is disabled in the BIOS for all CPU modes (VERR_VMX_MSR_ALL_VMX_DISABLED).
Codice di uscita: E_FAIL (0x80004005)
Componente: ConsoleWrap
Interfaccia: IConsole {872da645-4a9b-1727-bee2-5585105b9eed}"

Additional information:
- Teh PC is a Lenovo 2537E59 with Intel i5 CPU
- last night Windows updated to 10.0.18363
- A few days ago I upgraded to VirtualBox 6.1.12. Among various attempt I reinstalled 6.1.10 and 6.1.8 without success
- While trying to solve I noted an error message in the set-up of the virtual machine (translated from italian, english message might be different): "Hardware virtualization is enabled in SYSTEM-ACCELERATION but it is not supported by your guest system. Should be desabled...." I disabled it, however the error message stays and I cannot save the correct configuration

Thank you for your support

[scottgus1]

SOLVED THANKYOU

It appears you fixed this one yourself, thanks for letting us know!

Not in a hypervisor partition (HVP=0) (VERR_NEM_NOT_AVAILABLE).
VT-x is disabled in the BIOS for all CPU modes (VERR_VMX_MSR_ALL_VMX_DISABLED).

Hardware virtualization is enabled in SYSTEM-ACCELERATION but it is not supported by your guest system.

These could happen because either your PC BIOS does not have the "Virtualization Technology" (VT-x/AMD-V/SVM) turned on, or something on the PC, like Hyper-V or 3rd-party antivirus, is using it.
I have a 64bit host, but can't install 64bit guests will explain how to solve both of these.