Shit happens!
I broke my Computer and my Arduino sketch went away.
I have one Program, what is working just now in my Arduino Uno. ( and Im satisfied to it.)
Question: Is it possible to rescue from Arduino uno to my Computer. Like download it or is it only way that I write it again. ??
It is quite a long sketch and i did some modifications too, so it is not in my memory.
Timo 
You can retrieve the compiled code from the board, but it won't look anything like what you wrote.
And when I say nothing like what you wrote, imagine your favourite picture.
Now scrunch it up into a ball, put the ball in a blender, and switch in the blender.
How this retrieve works ?
(deleted)
You will probably have more success recovering the data off you bad drive with something like TestDisk / PhotoRec. What exactely went wrong with your drive?
Timo345:
I broke my Computer and my Arduino sketch went away.
Maybe you could connect the hard disk to another PC and recover the files. You can get "boxes" that can hold a hard disk and connect to a PC with a USB cable.
...R
Timo345:
Shit happens!
Sure does, and it willl happen sooner or later, so you need to plan for it.