Problem in creating a new virtual machine inside another

[Helloween]

Hello, guys,

Right now i`m having a tough issue: i`m trying to create a virtual machine inside another and it won`t start, it shows this message:
``Failed to open a session for the virtual machine andre.

VT-x is not available. (VERR_VMX_NO_VMX).

Result Code: E_FAIL (0x80004005)
Component: Console
Interface: IConsole {db7ab4ca-2a3f-4183-9243-c1208da92392}
``

how can i simulate my VMX into my virtual machine so i can use it on my new one?

if not(or not trivial), can i use a virtual machine inside another without using that resource?

windows used is XP professional 64, last version of virtualbox, computer is i7 3770, 16 gb of RAM, motherboard is a good asus and videocard is a decent nvidia one

[mpack]

VirtualBox does not reflect VT-x into the VM, so if the nested VM requires VT-x (e.g. a 64bit VM, Win8 of any flavour, or a VM which has VT-x selected in the recipe) then it won't run.

Be warned that nested VMs are in any case not supported, even if they don't require VT-x.

[Helloween]

so should i turn off VT-X?
is there a way so i can use VT-X on my first machine and then don`t use on my second one?

[Perryg]

Nested Virtualization is not supported.

If you can make it work then good but you will only be able to use 32-bit guests in the nested guest and nothing Windows 8 will work period.

[Helloween]

yeah, i don`t need windows 8 there, i`m thinking about using tinyXP, which is 32 bits,
but it won`t even start,

should i open my BIOS and turn of the VT-X and try without it or is there another way i can do with VT-X at least using 4 cores on my first virtual machines and giving 1 core to my nested virtual machine from there??

[mpack]

Turning off VT-x in your BIOS will only make it unavailable to the host as well as the guest.