So Mr. Low Technology thinks all those files were modified and deleted to clear the internet files to speed up the computer.....I wonder who told him that theory? It actually could be but I am not sure if they would show up modified....but system defragmenter could be to over write those modified and deleted files. I wonder what operating system this computer had on it....I believe that windows xp did NOT defragment on it's own, it had to be initiated by the user....seems a strange time to be worried about the system files on your computer right after your wife has passed away? I would think he would be worried about his children and how they were doing instead of modifying and deleting files on his computer..........