Shoutbox

I've tried downloading/redownloading Messenger many times now. And each time when I try to install it, it gets to the end and it says that it can't install because Microsoft Application Error Report didn't install. And then it says under that that something else is installing on Installer. I've tried many things, yet nothing has worked. It would be nice if someone could help me. I've got Vista (32 bit). Thank you!