VT-x Enabled But Still Got an Error

I still get the VT-x error after I have enabled it in BIOS. Any idea what may cause the problem?

$ vagrant up

==> mongod-m103: Booting VM…
There was an error while executing VBoxManage, a CLI used by Vagrant
for controlling VirtualBox. The command and stderr is shown below.

Command: [“startvm”, “88c0e0e0-18f6-4e15-8ed2-6fc3ed6ea82b”, “–type”, “headless”]

Stderr: VBoxManage: error: VT-x is disabled in the BIOS for all CPU modes (VERR_VMX_MSR_ALL_VMX_DISABLED)
VBoxManage: error: Details: code NS_ERROR_FAILURE (0x80004005), component ConsoleWrap, interface IConsole

$ lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 2
On-line CPU(s) list: 0,1
Thread(s) per core: 1
Core(s) per socket: 2
Socket(s): 1
NUMA node(s): 1
Vendor ID: GenuineIntel
CPU family: 6
Model: 23
Model name: Intel® Core™2 Duo CPU P8600 @ 2.40GHz
Stepping: 6
CPU MHz: 800.000
CPU max MHz: 2401,0000
CPU min MHz: 800,0000
BogoMIPS: 4787.95
Virtualization: VT-x
L1d cache: 32K
L1i cache: 32K
L2 cache: 3072K
NUMA node0 CPU(s): 0,1
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts nopl aperfmperf pni dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm kaiser tpr_shadow vnmi flexpriority dtherm

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Vagrant up –provision fails