Macrium Free is the way to go in my opinion. It has never failed me but neither has Windows own imaging program. You can use save Windows 7 images from different computers but it's kind of a kludge because you have to rename the folder from the default WindowsImageBackup to something else and when restoring, rename it back to default. When recovering an image, Windows 7 looks for that folder name while you can browse to the image you want to recover in Macrium. With Windows 7 you can recover from an unbootable computer using the Windows 7 System Repair Disk. Macrium will let you create a WinPE bootable disk that will do the same thing. If the drive fails, replace the drive, boot the Macrium WinPE disk and recover the image. Your back in business in minutes.
To be able to have multiple versions of system images saved on the same drive or partition, you would need to rename the older WindowsImageBackup folder from the previously created system image as described in the NOTE box at the top of this tutorial.
If you renamed the WindowsImageBackup folder for the system image version that you wanted to restore, then you will need to do the steps below before you will be able to restore that system image.
Macrium Free is easier to use and faster. Plus you can mount the images as a virtual drive to explore them. This is for MBR disks. I am not sure if you can mount an image created from the new GPT disks. You can also verify the image where Windows 7 cannot.