My sony vaio suddenly started restarting.it worked fine but after i restarted it and came back after 13 hours it wasnt working. pc starts from boot menu any option safe mode or anythign else doesnt work, it just loads windows logo after 1min a blue screen appears for half second and restarts again. Blue screen has some letters i didnt saw well but doesnt see to be any english or any other know letters. Also tried repair windows and any command for c:\windows says it isnt valid. I tried to see the disks from format screen and i can see that d is ntfs while c isnt anything. So what could have caused it? virus?Any way i can fix that? can windows be installed on c again that it isnt ntfs or fat32?