You can recover your data in this way.
Remove the hard drive and put it into an enclosure.Plug it into another computer as a slave.Then you can copy your files on it.
If it shows up in 'my computer' as a drive letter(like E: drive) but you can't access it,you can recover data on it with
data recovery program to avoid losing your data.I have succeed
recover data from crashed hard drive with Tenorshare data recovery. It can recover data after deeply scanning your hard drive to look for lost data due to drives crash, physical damage,system sabotage, virus attack etc.You can get it here:
http://www.any-data-recovery.com/product/datarecoveryprofessional.htm After you recover your data,you can format it to check out whether it can be fixed.
If the hard drive can't be detected,you can try this way.Put it in a zip-lock bag and put it in the freezer for overnight. Then while it's still cold plug it into the computer and you may be able to view it in 'my computer'. And if needed, run the recovery program to recover your data on it.
If it fails, you will have to go to a recovery office where supply data recovery service but let's hope not because it will cost you a lot of money and whether they can recover data is not guaranteed.