Following items can indicate a defective harddisk:

- The harddisk makes ticking sounds

- The harddisk makes a weird tune (serious !)

- The harddisk makes a shrieking or rattling noise

- The harddisk smells burnt; some parts can even smoke

- The harddisk is not recognised any more by the bios or windows / OSC / Linux / Etc...

- Windows / OS X / Linux / Etc... cannot boot anymore

- The computer stops reacting while you are at work

- Your harddisk suddenly seems to have an incredible capacity (e.g. 0 GB of 10000 GB)

- Your harddisk still appears in the bios but its normal name has changed

All these symptoms can indicate a defective harddisk.
In the four first cases its a matter of switching off the disk as soon as possible. Every second the disk is powered it can be further damaged.
If you manage to start the PC for a little time, immediately start making a backup of all your important files before the harddisk dies completely.

If, however, you are not able to do this any more, then send the drive to us. In most cases we can recover the data.