Windows Installer is broken

Hello,

My Windows Installer hasn't worked for some time. Is there a way to install Windows Live Messenger without using it?

Basically there's some strange install loop where something has been wanting to install but been unable to do so for the past... year, maybe? No way to keep it cancelled... hasn't really been a problem, except for any time Windows wants to install something official, because then it finds that the Installer is busted. Most of the time I don't care, but now they've changed MSN so the old version doesn't work unless you update it... so now I'm stuck unable to use it at all.

Not looking to fix the Installer at this point because I've already tried and even reinstalling it doesn't help (please don't tell me where to download it or something inane like that -- if you know how to permanently cancel something that's a different story). Just looking for a workaround.

Thanks!