If this is your problem , i'm sure you are hit by a surabaya virus . My 1st pc that i treat as my mistress attacked by this virus when my brother connect it to a psp and these is what happens to my mistress: All folders and files including windows OS folder disappears. Only few folder files with fixed size of 40K appears to user. , When you try to change the options for show hidden files, it doesn’t show the previous data. , You will not able to run many anti virus & software programmes. Installation also get blocked. , There are files like thumb.exe , System becomes unresponsive. After login it takes lot of time to user to operate it. ...Can someone help me here!!!