New to Acronis and backups

What you are wanting to do isn't something TI does. However, it may be possible to boot into Windows from an eSATA drive (if it's modified properly). Windows is designed not to boot and run from USB drives (which is what most people use).

You may want to consider having a spare internal drive handy to use if it's needed. A spare drive is also nice because it allows you to test the restore process without risking the original drive.

You can put 2 partitions on the external and save the backup images to the second partition. If your drive fails, remove the drive from the USB case and put it in the PC and then restore the image and MBR to the first partition of the drive using the TI rescue CD.

The first partition should be a primary and only needs to be big enough to hold your C drive. This assumes you only need one partition for your C drive. If your existing drive has multiple partitions and you need them then you should partition the USB drive accordingly and keep your image on a different partition. TI can't restore an image to the partition containing the image file(s) since one of the first things it does is delete the partion which would delete the image.

You have to enusre the drive in the USB case is the appropriate type (SATA, IDE) for the controller. In reality it is a lot easier just to go out and get a spare drive and they aren't very expensive these days.