OK. What you want can be done with backup software. But there are some details you need to investigate.
A few PCs can be set to boot from the network. Likely yours does not have that feature. The alternative is to have a CD or USB drive to boot the computer if the hard drive failed and was replaced with a blank drive.
The CD or USB drive must have a program the can read the special format used to copy the image of the operating system and the programs and data all in one integrated data set. The is often called an "image" of the hard drive.
To use
macrium reflect that way, you must first read over the documentation and practice on a spare computer. Personally I have used macrium reflect for a couple of years, but I would never tell somebody it is easy to understand. But with study and practice, you can do it.
Here are the two things to worry about:
Q. How to you start a computer without an operating system?
A. Change the BIOS to boot first from a USB device that has recovery software.
Q. How do you get the image that was placed on a network share?
A If needed, the image must be transferred to a portable hard drive .
These are the things That I have found to be areas of concern.
BTW:, some portable hard drives come with software.