In general an installed system on a virtual hard drive can be copied to a real hard drive. The distro may need some tweeks to get it to work. Tweeks may need to be in the form of driver support, boot by device id changes or such, grub entries. It may work like a champ first try but it may have you editing it for weeks. It may help to change it before you attempt to clone it. (trust me on this edit for weeks deal)
It is always best to use the installation program that the distro came with to install.
Last edited by jefro; 03-27-2012 at 04:03 PM.