If the drives can still be recognized by Windows, either connected directly or using a USB hard drive enclosure, software solutions like EaseUS or Recuva can frequently recover files, depending on how damaged the drive is. After that, you're going to need a data recovery firm that opens up hard drives in clean environments with specialized tools, and that can easily go over $1,000.
With hard drives, the only way to protect important files is *before* the hard drive breaks - think of backing up to one or more methods (extra hard drive, optical disk, cloud) as a basic part of PC maintenance, akin to changing your furnace's air filter or your car's oil.