Eccoci qua, e la stessa cosa vale per molti altri software che fanno il check della versione all'avvio dell'installer, basta sapere cosa c'è dentro... 
Been playing with the new MSN Search toolbar, it is VERY nice however at work I use Windows Server 2003 as my desktop machine (need it for some dev work). Well, it turns out that it is possible to do this - as seen (of all places) Slashdot - in short you just exctract the exe then use this command:
msiexec /i MsnToolbarSuite.msi TBSDEVCODE=1, seems just fine after that!
Oh, one other thing, to turn off the annoying buttons (which just take up screen real estate for me) go to the registry key HKEY_CURRENT_USER\Software\Microsoft\MSN Apps\DB than add a DWORD value called 'Buttons' with the value 1, turn off the toolbar then back on - buttons are gone!
Source: Installing MSN toolbar on Windows Server 2003