Just switch off the Windows Startup sound.
Or change it to something you actually like.
Start - Settings - Control Panel - Sounds and Audio Devices.
Click the Sounds tab and then scroll down the list until you see Start Windows. Highlight it and then go to the list of sounds underneath the scrolly box and pick a sound you do like or just select 'none' from the top of the list.
Or you can make it use any sound you like as long as it's in .wav format.
Just click on the Browse button and look for your sound.
I once had the computer play a quote from Marvin The Paranoid Android when it started up "Oh no. Not again."
Now I don't like it to make any noises unless I explicitly tell it to.
Can't stand websites that start playing bloody noises just because I've clicked on them.