Scenario If one has backup file of system image on a external hard drive. And then after a few days the os crashes. So to restore the system image, can one restore it after reformating windows on the internal hard drive or he has to create a bootable cd/usb? windows 7 installed in internal hard drive one takes a system image backup of the windows 7 os in an external hard drive after some days windows 7 crashes so can one reformat the internal hard drive and then restore the windows 7 image from the backup software?
Need more info as to what software was used to make the image backup and how the computer was configured. But lets assume that there was one hard drive installed and one large C: partition, and you used Acronis to make the image backup. First you will need to make a bootable USB drive using Easy2Boot or Rufus. Search MDL for how to do that. Then you will need to find a copy of the program that was used to make the image backup and copy it to the bootable USB drive. Be sure that the USB drive is large enough to hold the image backup image. Then copy the backup image to the USB drive and re-boot the computer. I f Acronis was used, you will have the option to zero out the internal hard drive, but it's not necessary but it doesn't hurt to do it. Then restore the image from the USB drive to the internal hard drive. Set Acronis or whatever software you use to shut down the computer after restoring the image. Remove the USB drive and turn on the computer. If the image was good, it should start up. Good Luck .