Suddenly, the file items (documents, pictures etc.) have started getting an icon of a shield and a recycle bin super imposed on them. It happens all of a sudden, they disappear after reboot only to reappear after a while.
If you have admin on the computer, try and go into the control panel and give yourself complete admin onto the computer. Then change the file security to make them the least protected, and allow all files to execute changes without your permission. Let me know if the shield goes away.