Not sure what you are doing.
At a guess you are using Windows Backup - it will not save a backup onto your system/boot partition , for obvious reasons.
It therefore tries to save it to the only other partition available - the manufacturer" recovery partition" ?
This stops the warning - but does not solve the problem about what to do about the backups.
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]
"NoLowDiskSpaceChecks"=dword:00000001
If you have an external drive - save backups to that.
If not - and you have enough space, save the backups to another partition - create one. Try not to mess with the "recovery partition" at all.
I suggest using a Macrium Reflect Free to make an image of your o/s partition - make a new one every now and again . You can restore that image from the Macrium boot disc ( you run it off from within the macrium program - dot the Linux option and burn it to cd. )
Macrium Reflect FREE Edition - Information and download
You can merge this .reg file to stop the warnings for now:
View attachment NoLoDiskSpaceCheck.zip
Hope it helps