Windows 7: ID full backups? Says oldest date range is most recent

Trying to delete old backups to make room.

How can I tell which backups are *full* backups? (please continue reading to see why the obvious answer doesn't work)

Under Backup and Restore > Manage disk space > View Backups, I select *oldest* Backup Period (there are 4), hit Delete, get a cautionary message:
"Are you sure you want to delete the most recent file backup?"

If I select any of the more recent Backup Periods, I only get a standard confirmation request (i.e., without "the most recent")

I don't want to delete the last full backup until I've made a new one.
"Create new, full backup" is NOT in the left pane options list in the Backup and Restore window.
The past several regularly scheduled backups have failed ("was cancelled"), I suspect due to lack of space. (Backing up to a networked RAID array, avail space only 1TB, backup size approx 1 TB)

3 of the 4 Backup Periods are sizeable, but as I've downloaded lots GBs of image files in this time, I can't tell if the oldest Backup Period is the only one with a full backup or not.

Hello Kitty, and welcome to Seven Forums.

In Windows Backup, each dated "Backup Set" folder is a new full backup period. In this folder are dated incremental "Backup Files" folders.

Whenever you create a backup in "Windows Backup" by clicking on the "Back up now" button, it only creates an incremental backup (Backup Files) again.

Backup User and System Files

If you like, you could use the shortcut in the tutorial below to create a new full backup period ("Backup Set" folder) each time it's used.

Backup - Make a "Create New Backup" Shortcut

Hope this helps,
Shawn

Thanks, Shawn, that clarified it nicely.

Confusion was due to different nomenclature/file structure showing depending on whether backup files were accessed via Windows Backup vs Windows Explorer. Dunno why. Don't care. All better now.

Many thanks again.

JP

You're most welcome JP. Glad it was able to help.