Windows Image Backup Fails--No Matter How Large the Backup Drive!

I'm building a new web server to replace a nearly 20 year old Dell machine that died in a power surge last Saturday.

Build is 21H1 19043.1348.

I've several Win 10 Pro systems and never encountered this particular error with backups before. Windows Image Backup has up to now, been reliable for me.

This new system came pre loaded with Win 10 Pro and an Admin account. Logged in as such, I cannot backup the 32GB bare bones Windows drive. I first tried the second internal 240GB drive, then a 1TB ext drive, then went out and bought an 8TB ext drive and each time the backup fails with an insufficient space error.

Research on this problem said something about running checkdisk, but when I tried that, I got an error that I don't have sufficient permission (as an admin) to perform this task.

I'm trying to make a backup image before I make major changes, so I have a baseline to return to. This is a fanless industrial PC with no optical drive--only internal SSD drives, so I cannot use something like Macrium on a CD to make a backup and restore.

Here's the error. What's causing this? Is it the way the manufacturer set it up, perhaps they locked down permissions too restrictively? How can I make it work properly?

Hi,
I primarily use free macrium reflect
More specifically it's winpe recovery media which the os is not active

But once you create the winpe it will show a driver check list

If System Image has been deprecated, why is it still there?

I use System Image frequently on my other Win 10 machines. It's saved me numerous times after incidents that rendered the system unable to start or be repaired.

All the systems where Backup Image works are built by me. The system where it doesn't work was built by the vendor that sold the PC. I am wondering if that's because it's a "latest version" where the feature is broken, or because the vendor did something to cause it to malfunction by misconfiguring Windows?

I've tried Macrium in the past, but there were problems with the graphics driver not showing the whole application screen, making the application impossible to use.

It seems to me there ought to be a way to make this work.

I've run into this when the hidden system partitions have a significant amount of space consumed. I've experienced this in the past, and somehow (I cannot remember how), I got space freed up on these partitions on my primary hard drive and got past the problem.

I believe your lack of space issue is with the source (32GB) system drive - the error message seems to make that clear. I imagine it may be tight on space, but there must be some crud you can remove. My complete C: installation (with any number of programs) is only 24GB.

My system drive is 128GB but the Windows installation is only consuming 32GB. The system drive is mostly empty. Not sure about any hidden partitions though. I don't have control over the system reserved partition which is around 100MB.
Is 128GB enough for a boot drive? I thought it was more than enough so I ordered the PC configured with 128GB system drive thinking that was overkill.