There are many free drive image/backup software packages.
One of them is :
http://clonezilla.org/Physical backups sound nice, but there is a risk.
Many people are using it, but are forgetting a very important thing.
They don't store the backups a decent distance away from their system/home.
Let's say a large fire breaks out at your home.
Poof, gone is the system as well as the backups.
Some ISP's give their clients some free space for a website, check if yours does too.
If it does you can use that space as backup location and you don't have to use a cloud service.
On a side note:
What they nowadays call "cloud" is a misnomer.
The cloud = The entire (inter)net
It is believed to be invented/developed by Joseph Carl Robnett Licklider in the 1960s with his work on ARPANET to connect people and data from anywhere at any time