Hard Drive data recovery after formating

Help PLEASE. Is there any way to recover/restore the data on a Seagate Model ST32D413A 20 gbyte hard drive. The computer is a HP Pavilon 8550C. A “helper” put the drive in another computer and it automatically reformatted it. My job could dependon my recovering/restoring the drive.

I thought asking the question would help me cut down on the research time as I need to get the problem corrected ASAP…Your help will be greatly appreciated.

Thank you in Advance