Disk Drive Disappeared?

I have a 300gig disk which has just disappeared? it was there one moment and then gone the next? I have looked in disk management and it is gone from there also? what could have happened? I can see it it physically but of course windows is not doing the same? Dare I ask could I have lost all my data? and using that word 'lost', is there a way of retrieving what was on that disk? One hears all these stories of police authorities being able to retrieve what was on a disk when it has supposedly been wiped clean by it's user, and I do not have anything sinister on mine, I am hoping I can recover my files, crikey I am well peeved off, maybe the disk is dead, I guess even disks have a life span, but then again it is only 3 years old? HELP SOMEONE PLEASE???:cry

 

have you tried hooking up your hdd to another computer? if it works on another computer, it might be a software problem or even bad mobo connectors. always check your cables.

if you do get it working again, but have lost all your data, a good program to recover it is NTFSUndelete (http://ntfsundelete.com/)

 

Thank you for your reply, I shall certainly attempt all the things which you recommended and let you know!