get the HDD out of the computer, then get a HDD to USB adapter
and try to read the date from the HDD (i recommend usinge another machine)
if it works, make an backup and then format the drive.
it's very implausible that a working machine does just crash.
he fucked it up for sure and now he's being a bitch not telling you!"
seroiusly, that'S the main reason why i always act like a pussy when someone wants to use my PC,
they all say don't be a pussy and i just say, FUCK YOU, MY PC, I USE IT AND NOBODY ELSE!
cheers
S.