virtualbox.org

Hello everybody.

I was trying to install FreeBSD 8.1 amd64 on VirtualBox 4.04
My host OS is Windows 7 x64.

VirtualBox gave me a warning about VT-X not being enabled, although I knew it was.
What I did was that I disabled Intel TXT (Trusted Execution Technology) on the BIOS.
This setting hides CPU information from the applications to prevent software based attacks, but also hides the 64bit capabilities to VirtualBox.
Ater this VBox stopped complaining about my 64bit guests

Hope this helps someone!

That is very interesting. It could explain what is happening in a few cases that have appeared in the forums recently where all the settings looked OK but VirtualBox still reported no 64-bit support.