Computer wiz needed!

[Pimpin Dsmstyle]

I had someone on this site build it for me. I remember registering it, i just have no idea what I did with the key. I don't think there are any stickers on the computer since it was home made.

A guy I used to game with told me you can find a program that will "decode" your key or something. You download the program, run it, and it pops up telling you what your key is. That's kind of what I'm looking for. I just don't know where to find it