Is that program downloadable? If so where?
For a list of applications, most (if not all) of which support noise reduction,
check out this other thread. Audacity is the only truly free option.
The whole thing is always inaudible when it is done recording, so that is why I have to bring up the gain everytime. I just brought it up way too high I think and can't fix it now.
Two things:
<1> Sounds to me like <a> you had a low-level master file, <b> you bumped up the levels, and <c> you bumped them up too high and want to fix the high-gain file. Why not just go back and re-apply the gain to the original, low-level master file? (Or did you overwrite it? Oops!)
<2> For the future, try getting your levels up high enough while recording so you don't have to amplify in post - MUCH better results.