With something as valuable as a year long thesis, you should be able to use the backup that you saved to a DVD/CD or flash drive? If not, I'm sorry as hard drives will ALL eventually fail to work. Hopefully that's not the case here.

In your case, make sure that your external hard disk case is able to function correctly with the smaller laptop hard drive.. In addition, what type of computer operating system did you plug the USB drive into? Be sure to try it on an XP computer which has better support for USB> Make sure to plug the USB cable into a USB port on the BACK of the computer. (USB ports on the front of a computer frequently don't work as well.) Did you try plugging the USB cable into a USB hub? It can frequently allow it to work correctly.

And if all else fails, there are professionals that might be able to extract the data from your dead hard drive. See the link below:

http://www.ontrack.com/datarecovery/

Hope this helps.

Grif