Unfortunately, I'm using the Win B&R. So you are suggesting using another B&R? Any particular one?
The standard recommendations on this forum would be Macrium Reflect Free Edition or maybe Aomei Backupper. Both free.
You can make your life easier if you had Windows on one partition (C) and your data on another partition. I assume your Windows and data are all on C. Am I correct?
I'd rather you backed up your data (not Windows) in an ordinary manner, file by file, without using imaging at all. There's at least a half dozen free applications that can do that. Imaging is something of a complication and to that extent carries some risk of failure. Failure might be fine for Windows because you can always reinstall Windows. Not so fine for data because at least some of your data is likely irreplaceable. And who would want a surprise when a drive fails and you have to resort to your data backups---only to find that the backups can't be accessed for whatever reason?
How about just deleting the current backup files, and letting B&R doing its thing with my weekly schedule, 1:00 AM on Monday?
Not sure I'm following you. You could of course do that on any new larger external drive you bought.
If I go to a bigger drive, how do I get the current backup to the new drive?
I'm not sure how easy that is with Windows Backup and Restore.
If I bought a new backup drive, I'd probably just make a set of new backups directly from my originals, with whatever application I chose.
P.S. Is there some way to backup the system image? I vaguely recall one is made on a CD/DVD disk when the PC is first setup.
A Macrium image of a partition creates a single file with an mrimg extension. That single file can be copied anywhere it will fit, just like a random picture of your cat.
I have no idea how easy/difficult that would be with Windows Backup and Restore. Considering its known crankiness, I'd expect some issues.
One of the advantages of backing up data file by file, directly, is that the resulting backed up files are simply duplicates of the originals and can be copied, deleted, or moved at will, like any other file.