Keep my files removes your apps and settings, but keeps all of your personal files. Remove everything erases your apps, settings, and personal files. If you don’t have a backed up copy of your files, you may want to press Cancel, back them up, and begin this process again.
Choose Just remove my files if you are keeping the computer. Opt to Remove files and clean the drive if you are selling or getting rid of your PC. Note: This can extend the reset process by a few hours.