This has happened because you put the drive into an external enclosure.
Free and easy answer: Download Kubuntu and Linux Live USB Creator (Lili)
Create a Live Linux USB disk with persistence using Lili
put the bad drive into the laptop and boot from the USB stick (see manufactures website about BIOS settings)
You can now access the drive without the enclosure and burn the files to disk, move files to another disk, or move files to another networked computer
This is a very common question. Quite a lot of guys have met up with it. Just relax for it is solvable. Open the following page and dowload the freeware which is professional at recovering data loss due to "do you want to format it now" problems.
Page: http://freeware-recovery.blogspot. [...] overy.html
The freeware allows you to preview the lost data so you will decide which to recover. Do as the page tells you and you will find it quite simple.