You'll be lucky to get your data back from the hard drive especailly If you have re-installed your o/s and other programs to the drive. There are a lot of HD recovery progs available though, just do a search on GOOGLE and try some.
Be vey careful of installing the recovery progs on to the drive that you want to get the data from. You could easily overwrite the stuff you want to recover.
If the data is that important then it may be best left to the profesionals to look at your drive/data backup.
There is a lesson to be learned here - Always verify backed up data to make sure a) That is readable and b) You have backed up the data you intended to back up.