Windows 7 backup, deleting old backups

I’m having to use the built-in Windows 7 backup on my work PC, but I’m running out of space on the backup drive (USB hard drive). There is a “Manage Windows Backup disk space” dialog box that lets me delete old backups, but it says “all files backed up during the selected period will be deleted.”

So, if I delete the backup from every period except the past 5 days, will I no longer have a full backup? And the only files backed up are the files created or modified in the past 5? Or will I still have a full backup, I just can’t restore files I deleted 5+ days ago?

OK, STOP, do not do anything until you understand what kind of backup you have running. For a work PC, go to whoever is supposed to know about backups.

I administer my own work computer, as most scientists do. I have multiple copies of my working files in different places. The Windows backup is only a last line of defense.

Now can you answer my question?

I am pretty sure you can delete the older backups safely enough. (If not Microsoft Backup would not be offering it as an option.) Ideally, keep the last backup and the one before it, but if space is truly tight, the one before can go too. The only at likely circumstances under which the older backups would be useful is if you wanted to recover a file deleted several backup cycles ago.