Backup takes 800GB? Manage Windows Backup Disk Space

How do I control how much disk space my Windows Backup takes up? I have a 1TB external disk for backups and other files. My computer's HDD only has about 250GB capacity. I don't know why my backups file got so bloated. What should I do?

I see that I can delete the older backup file: 22-Oct to 11-Nov. But read the text.
""Deleting previous backups will free up space on your backup location."
So far so good.

Then it continues, "All files backed up during the selected period will be deleted."

I'm pretty sure the text is just badly written. I guess that means the backup-files (on the backup drive) will be deleted. They couldn't mean that the original files (on my data drive) will be deleted. That sure is a scary possibility though. How do you understand this?

System: Windows 7 Enterprise

ScreenCap below

Based on your screenshots, these appear to be multiple backups. Unfortunately, Windows Backup is not performing an incremental backup but will always perform full backups. This is why you have 2 full backups taking up 800GB. A system image is also being built, which is a very good thing, but will require additional space. Windows Backup gives you a relatively easy way to do backups, but does not have much of an enhanced feature set. For a more robust type of backup, you can do one of two things. Either increase your storage media so that you don't have to delete old backups as often, or purchase a commercial backup application like Paragon Backup & Restore or Acronis True Image.

I hate to have to give you this type of advice, but it is merely the truth. Windows Backup has many limitations. In one of my video tutorials, I explain how to do a very safe offline bare-metal disk image using Paragon Backup & Restore. This is a fool-proof way of maintaining a very, very accurate backup of your system. Incremental backups can also be made based off the original.