What you see if you turn off VT in BIOS

This is what you see with Virtual Box trying to run a 64 bit guest:


This is what you see for Windows 7 Virtual-PC trying to load XP-Mode


Both VMs have been successfully configured with AMD-V (SVM) enabled in BIOS - you will not be able to configure the VMs shown above if your processor or BIOS does not allow you to enable virtualization.

The Sun VirtualBox will run a 64 bit guest o/s ONLY if AMD-V or Intel VT is present and enabled. Microsoft Virtual-PC can ONLY host a 32 bit guest irrespective of the virtualization capabilities of the system.
In addition, the Sun VirtualBox will host a 32 bit guest even though virtualization techologies are not present.
This means that if you have a licensed copy of 32 bit XP you can run XP in a VM using VirtualBox on a Windows 7 64 bit o/s machine and then run DVD decryption programs such as DVD43.