How to replace a dead hard drive - Toshiba A45-S121 Notebook

no hDD lasts long 5 years
ALL FAIL AND ALL DO THAT AND THE OS IS DEAD.
WE replace it and reload a fresh OS
just like bad tires on a car, replace all that.
is the screen100% dead as most are now due to dead ccfl backlamp tubes?

Is the "dead" hard drive 80GB? or 500GB?
I presume you set up this hard drive as the second hard drive, or as an external drive. You can do these:
1. Disk Management (check the readablility):
Control Panel, Administrative Tools, Computer Management (please run as administrator; right click it), Disk Management. Is this hard drive info exist in this screen? If it is, then the hard drive is not dead.
Click on the hard drive info, right click, and you can do some actions (format, expand the volume, assign a drive letter, etc.)
2. If necessary, test and fix it using Norton Utilities (download and run it):
http://download.cnet.com/Norton-Utilities/3000-18512_4-10907620.html

That sounds like you have a dead hard disk drive if the hard disk drive is dead then you will need to have it replaced there is a way to check if it is dead or not, you will need to go into the bios for most it's usually the hi lighted tab when the bios comes if its dead the hard drive slot should say empty or none if it's not dead it will show the hard drive info

unlikely to get a board
dead is dead for most hard drives
however there are people who collect dead hard drives and can interchange boards as the failure can be the reader arm or laser and the board is in good condition
ask around the computer repair shops for anybody that they know off

the hard drive has to be replaced....there's no other solution....a clicking hard drive means a dead hard drive!

Change the harddrive. I have a 20 gig drive from a dead 910. Drive is 100%.

Remove the hard drive, insert a new one and install Windows. Use your recovery disk.

You can replace the hard drive, but you will need to reload the Operating System from some other source, as it sounds like your Hard Drive is dead.

Disconnect any leads and remove the outer cover.

Check the hard disk inside is securely pushed into the receiving socket.

Replace outer cover and give it a try.

Sometimes a knock can dislodge the drive and cause the problems you describe.

Best wishes.