Backup files are saved by default into the folder "C:\Program Files\RegHealer\Backups". You can browse this folder with explorer or quick open it from the Start menu -> Programs -> Registry Healer -> Backup Folder.
In backup folder you can view all created backup files. They have filenames of "id_yyyy_mm_dd.reg" format, where id is an identifier ("paths" for invalid path entries and "empty" for deleted empty entries) yyyy - year, mm - month, dd - day of creation date.
Double-clicking on a backup file in Windows® explorer all information from that file will be restored to the Windows® registry (after your answering "Yes" on the confirmation dialog). Files with the ".reg" extension are Windows® registry saving files.
If you have found a problem with your computer after using Registry Healer you may restore the most recent backup file. Then check for the problem again. If problem persists you may restore all backup files one-by-one in their backward creation order (first created - last restored).