But now I am confused since you say macs don't have bios.
You can't do anything about it, just use Parallels as usual.
Intel VT-x technology is enabled on Intel-based Macs. Make sure your Intel-based Mac has all available EFI updates installed; also update any third-party virtualization software.
Only Parallels 6 is fully compatible with Lion, AFAIK.
Mac don't have BIOS, Macs use EFI. Apple has made the EFI not accessible by users so changing something won't be easy. What exactly are you trying to change?
This will help eliminate which part of the puzzle is the cause.
Are you using a Developer Preview of Lion?
Those issues are only known in the DPs.
What do you mean?