I just got a .iso of the linux distro Backtrack 5 R2. I set it up, using virtual box, and set it up to run using the .iso, and hard drive as a .vdi. Here's the setup:
System: Base Memory: 1500 MB Boot Order: CD/DVD-ROM, Hard Disk Acceleration: VT-x/AMD-V, Nested Paging
Storage: IDE Controller IDE Primary Master (CD/DVD): BT5R2-KDE-64.iso (2.62 GB)
SATA Controller SATA Port 0: Backtrack 5 R2.vdi (Normal, 8.00 GB)
Why would I be getting this error? Everything looks fine to me. And also, I'm running virtual box in a Windows 7 64bit OS.