Are you sure that your antivirus is reliable? What AV are you using? Try to download antimalware like "Malwarebytes".I think that you have a virus or trojan.
something really weird is going on, i use my computer for photo editing alot, over 18000 pictures, first i noticed that certain photos will pop up in another folder, files on the desktop that are moved or deleted come back and now when ever I try to save a file windows restarts. i have a gateway, using windows vista home premium. i've run several scans of my virus software with no results. please help