There are 3 main types of this backup process, in other words, and in this case, system imaging. You create an identical copy of your system partition with its master boot record. Here. I am talking about full backup (creation of the whole system image at once, and all over again when needed). Incremental and Differential backups are another story.
- Creating a system image from within the Windows
- Creating a system image from a program's assembled files prepared to be launched at execution of boot menu command entry (Some programs don't have this feature but most modern software like Acronis, Macrium, AOMEI, Paragon, Minitool and Easus implemented that option)
- Creating a system image from a bootable media (CD/DVD or USB) previously manually created by you. Nowadays many programs have that feature and it's basically creating a mini operating system with all original files that backup & restore program needs to function. So this is a completely independent operating environment that usually runs from RAM and probably the best option in terms of security, speed, and resourcefulness. It can save your system from whatever happens to it, excluding hardware problems, of course.
I am using the third option, having a bootable version of Acronis that I use for both backups and restore from outside of Windows. But it's a paid software. Good alternatives are AOMEI and Macrium, from my experience. As
@cruelsister mentioned, you don't backup system every day, but once per week, or once per month (preferably). Paranoid users can do it more often if needed, but as the process of creation takes a relatively long time (depending on hardware), just initiate the backup before you go to sleep and check the option to shutdown the computer after it finishes.
For the creation of bootable USB, most programs, as said above, have already an option built into the program that will do the job for you. You just need an empty USB. CDs are becoming obsolete. After creation, you are ready to go. So once you turn on your computer, enter boot menu by pressing certain key on your keyboard (usually F2, F8, F12, Delete, Escape, depending on your motherboard model), and initiate boot up procedure from an USB device (you may need a little setup in your BIOS, UEFI settings).
Check how I do this :
How-to Guide - BoraMurdar's Fix Tools
In this, I must say very clumsy video tutorial, which I made almost 3 years ago you can see how you can create a system image from a Hiren's Boot CD, actually miniXP environment in which Macrium Reflect PE Edition was installed. The procedure is basically the same for every other program of this kind. Macrium Reflect v6 has an option to create a rescue medium using Windows PE rescue environment, which is more compatible with modern hardware components.