I have just purchased a new Western Digital external USB hard drive (500GB) and i would really like some recommendations for some good reliable hard drive image backup software. I would like to backup my entire primary internal hard drive to the external drive so i can simply plug this HHD's USB port into another computer, (not before checking bootup priority in the BIOS) and have my entire system at the ready on the fly on any system. I would like the softwate to be able to copy back from the external hard drive to a main internal hard drive if incase of course one day my primary HDD decides to fail. Price isn't really a factor as much as reliability. I am using Windows 7 64bit on Intel core i5. Some peace of mind would be great in this matter.