I would try to copy everything you can from the drive right now on any machine that read it. Try both dektop and laptop. And stop using the drive as soon as you can, it is starting to fail. Like someone else said, don't write anything to the drive, it will prevent your ability to recover existing files...

The cost of a new drive or the Carbonite system is trivial compared to the time you put into scanning.

If you are looking for good, free backup software (like backing up files from an internal drive to an external one, or from an external one to a USB for example), SynchBack makes a good free one:
http://www.2brightsparks.com/downloads.html#freeware