Computer not booting up at Wellesbourne

Good afternoon for our Last job today we are with a customers in Wellesbourne, We are here because the customer computer is not booting up and giving a “non-system disk or disk error replace and strike any key when ready” error to repair this we loaded the recovery console from CD and tried to read the drive this failed so we ran the recovery program this claimed to have fixed many faults and the drive was read able again. We rebooted the machine and all was fixed the customer has been told to back up any important or irreplaceable data like pictures in case the machine fails again.