Need help recovering my bitcoins
First step: stop using that harddisk absolutely immediately. Either get a new one and start using that or make a complete image on the byte level (for example with dd in linux). Any write action you do on your current disk may overwrite your private key (assuming it hasn't already).

For further steps you need to provide more info.

Which bitcoin wallet were you using?

Was your wallet encrypted with a password, do you remember?