To recover lost files in windows 10 without a backup, it is recommended to install a reliable data recovery application that can scan your disk drive and find missing files (documents, photos, and folders). Such tools will identify file remnants even those that have been deleted off-hand. Leaving the drive idle will aid in curbing overwriting. System restore or command-line utilities can also be tried to recover lost files which are hidden or inaccessible when there is corruption.