When booting cd images from an new VM using Bios based emulation, i am able to, but when its UEFI, i cannot.

is there a way to change UEFI to bios and visa vesa without creating new vm again  ?

e.g. when i backup using Symantec Recovery 2013, from Windows 7 (UEFI), and boot to cd afterwards to restore (to test), it cannot boot, but when  i create new BIOS based vm and add existing backup dive it boots to cd, but cannot restore as  "UEFI partition cannot restore to  BIOS based system"

Can i switch from BIOS to UEFI, and back by editing vmx file ? That would be allot easier.