Cannot add 2nd processor

[iBright]

Hi,

I'm running VirtualBox 5.0.8 on Windows 7 Pro. The workstation is HP Z230 and CPU is Xeon E3-1226 v3.
After creating a vm, I tried to change number of processor but the control was disabled.

I tried on my notebook with Core i5 and it can add up to 4 cores.

Anyway I can add the second core to this workstation ?

BR,
iBright

[mpack]

Enable VT-x in the host BIOS and make sure nothing else is using it (like Hyper-v). VT-x is required for allocation of multiple cores to the guest.