Files deleted from the system folders, including viruses often end up in the system volume information folder unless system restore is disabled, just windows being helpful
thinking you might just have made a mistake you might want to restore
Disable system restore, this will clear ALL restore points, reboot, scan again and if clear enable system restore.
Read the info from the link in my signature DropMyRights as to how you can stop viruses/malware being able to put files in the system folders.