"Start Windows" theme

I just subscribed to this newsgroup and did not fine my question asked by
anyone else. Hence this post:

I have a .wav file that I want to use as the "Start Windows" sound. I have
already saved the file in a new scheme. The file's playing time is about
three minutes long.
(I did the same thing for my wife's computer and that sound file [The NCIS
TV show theme] works fine.)

When I test the sound file, it plays the complete file - but when Windows
boots, it only plays for about 8 seconds.

I don't know what causes this.

Can anyone help?

BTW, I just saw my name used by another "Webster".
I'll change mine if it becomes confusing.