If you don't want to use Google Photo Backup (sometimes called "Google Photos Auto Backup" and "Desktop Uploader"), uninstall it as follows:
To Uninstall Google Photos Backup:
- Click the Start button
- Click "Control Panel"
- Find and select "Programs" and/or "Programs and Features"
- Find and select "Google Photos Backup" in the list of installed programs
- Click Uninstall
NOTE: Earlier versions of Google Photos Auto Backup were called "Google+ Auto Backup." Uninstall it as described above.