Suggestion

I need a program that lets me amplify my microphone input, something that can preprocess the audio stream before any other program gets it.  Any good ones?

You're better off buying a pre-amp for your mic that amplifies the signal before it gets into the audio card/chip. Much, much better quality. The built in amplification function of Windows, as well as any other program that amplifies the samples, will amplify the noise you get at the point where the AD-conversion happens. With an external pre-amp it will be a lot better.