How to mute the sound output on Windows Start up?

"Apparently I misunderstood your question.

Edit: I found an even better way:

Auto Mute is a portable volume control
software that provides access to
several interesting features. It can
for instance be used to automatically
mute sound on logoff, suspend and
shutdown so that the next system start
is quiet.



A global shortcut is offered
to turn sounds back on after the
computer system has been started. The
default shortcut is Ctrl F10 which can
be changed in the program’s options if
necessary.

The only other options provided by the
volume control software are to run the
program during startup and to play a
computer beep sound whenever the state
of the sound changes from mute to on
and vice verse.

Auto Mute is a portable software
program for the Windows operating
system. The program is compatible with
many Microsoft operating systems
including Windows 7 and Windows Vista.
It can be downloaded from the developer’s website.

Else you should have a look at a very old program called: SetVol

It might still work under Windows XP. The description reads:

If you have multiple users using the
same computer, this application can be
used to adjust the volume level
automatically every time a user logs
on. SetVol lets you make custom
shortcuts for setting the volume of
the sounds your computer makes.

If you use + or -, you can create
shortcuts that increase or decrease
volume in increments of 10%. For
example, a shortcut that makes the
volume 10 percent louder would use the
command line Setvol.exe +10. On the
other hand, you can also omit the + or
- to set the volume at an absolute level. For example, the command line
""Setvol.exe 100"" would turn the volume
up to the max.

You could then set up a startup script that will automatically runs ""Setvol.exe 0"" muting your system.

For everyone else: try turning off the Windows start up sound?

Go to Start --> Settings --> Control
Panels then selecting the Control
Panel ""Sounds and Audio Devices"".

Click on the ""Sounds"" tab and it'll
look like this:



Scroll down just a bit and you'll find
Start Windows and Windows Logon:



Those are the two you want to change
or disable entirely. To change them,
click on the pop-up menu that
currently says ""Windows XP Startup"" on
my screenshot above.

To disable them is a bit unintuitive:
You need to also click on the pop-up
menu, but this time you're interested
in the top option:



Select (None), click on ""Apply"""