Is it possible, and if so how, to recover data from a formatted disk?

So this is how it happened. Many years back we had a Gateway computer with a 30 GB hard drive and the OS was Windows ME. One day it would not load properly so I decided to reinstall the OS only. Unfortunately, that did not solve the problem. So I ended up ordering Windows XP and formatted the disk. Tried reinstalling Windows ME while waiting for new operating system but install only went to 20 percent. Never messed with the disk again until this year to see if it still spins and what not. The real question is, do you think by trying to install ME that last time, that it is possible the disk was overwritten? I've recovered data from a formatted disk before but this is a different case. Also, if you know of any software (free or $) that recovers data let me know. Thanks.