In that case you do want normalize, and it seems there's a Windows port:

Normalize home page

Or just download
http://www1.cs.columbia.edu/~cvaill/normalize/normalize-0.7.6-cygwin.zip (I haven't tried this, but I'm familiar with the Linux version)

If it's like the Linux utility (most likely) you just open a MSDOS command line in the directory where all the files are - like I said earlier:

C:\PATH\TO\MY\WAV\FILES\> normalize *.WAV

There won't be a faster way!

Anahata