Uninstall Windows Messenger

Can anybody tell me the difference below.

I was given this script below to uninstall Windows
Messenger and some other instructions to remove it from
the Add/Remove Programs

RunDll32 advpack.dll,LaunchINFSection %windir%
\INF\msmsgs.inf,BLC.Remove

However, why do all of that if you can go into the
Add/Remove Programs | Add/Remove Windows Components to
uninstall Messenger. Wouldn't that be a lot simplier?

Also on another machine, I tried to do remove Windows
Messenger from the Add/Remove Programs | Add/Remove
Windows Components, but Windows Messenger wasn't listed
on that machine. Why?