Failed to bring 64-bit Guest OS up on a 64-bit OS

[ceo_nikka]

My host Specs/OS:
Intel Xeon 3.2Ghz
Intel Server Board SE7520JR2
Windows Server 2008 R2 64-bit

I have latest Virtualbox 3.1.4 r57640 and I am trying to bring same OS has guest (i.e. Windows Server 2008 R2)
However it is failing with following message:

Status: 0xc000035a
Info: Attepting to load a 64-bit application, however this CPU is not compatible with 64-bit mode.


Well I am not sure whats going on here. I already have a 64-bit host OS. Why the same CPU is not good for guest OS?

[dmcgraw]

To run a 64-bit guest in VirtualBox, you need to have hardware virtualization (VT-x) support. Your CPU, motherboard and bios need to support this.

First check in your bios to see if there is a setting to turn VT-x on. If not, check the specs on your CPU and motherboard to see if they support it.