Clicking, grinding or scraping noises indicate a head crash — the read/write heads have come into contact with the media surface, causing severe destruction.
Situation/Symptoms
Unusual noises - clicking, grinding, metal scraping.
What to Do
1) If booted up, back up any critical files.
2) Shut down the computer and DO NOT reboot.
Why
Extensive physical damage and permanent data loss can occur in a short period of time if a drive is left running.
WARNING: Tampering with a damaged disk may cause data loss.