a Recovery disc or a system generated backup May... or may not work.
Frankly in 20-odd attempts with personal systems external backups have worked ONCE.
On the other hand maintaining a recent "clone" of the system drive
As has been mentioned above, I use Clonezilla to create a backup drive.
After making sure all updates are installed (for the OS and all programs)
and defragging all partitions (auslogic disc defragmenter) I make a clone
After making that clone I then boot the system from the clone to verify that it works, generally if the system boots on the "clone" it'll work when you need it to.
Try demonstrating that a "Backup Disc" works.... you can't "test" a backup on a working system and if it doesn't work on a crippled system what do you do then?
My thought has always been that a spare hard drive is cheaper than buying a new copy of windows...
With a clon e EVERYTHING is preserved
I used to use three drives in rotation for my OS clones so at any given time I had the "active" drive, a week old clone and a two week old clone
But I currently use only two drives and make my clones monthly.
All data (media) and system settings are backed up seperately & redundantly