HELP! How to DOWNload Arduino sketch (harddisk crashed)

Regarding your PS: NO.

Nowadays there are so MANY options for backups. 16GB usb sticks (and even very fast ones) are so cheap these days...

And if you should be running a decent operating system, I recommend using GIT for code. It is sooo nice to have access to the complete history of what you did. You can go back, look at the differences, add comments (so you can remember why you did what you did)...