Is WD Backup Incremental?

I actually have two questions regarding backups to my WD My Passport 4TB External Hard Drive (WDBYFT0040BYL-WESN).

  1. I’ve been using it for a year to backup my Windows 10 PC as well as another external HD. I use the included backup software, which is WD Backup. It seems to be working fine, but the 4TB drive is at 30% full and that percentage has been growing. I realize the space used depends on how much I’m backing up and how much I’m adding each day. My question is whether the WD Backup is incremental or not?

  2. After every backup, I get a warning message telling me there were files that were not backed up. These all appear to be Windows system-type files. Do I want these backed up? If NOT, is there a way to exclude them (without individually selecting each and every one of what appears to be hundreds)? If I should be backing these up, is there a way to make WD Backup include them?

WD Backup creates a backup of updated files only if first backup has already been run. It automatically excludes some Operating System files, library files and these files won’t be added in backup data. If you want to take backup of such files, you need to manually copy them in My Passport drive. You can refer below link to check the excluded data files which will not backup using WD Backup: