nuts

My partner has recently had broadband fitted. He's running windows ME. He had a few problems with the broadband at first, but has sorted that. The problem is that last night his msn messenger was working fine - this morning, however, its saying he needs to install the updated version. When he goes to do that, it says he needs to update internet explorer to IE6. When he goes to do that, it gets to 77% installed, then says unable to complete installation, that a previous installation needs to finish installing (or words to that effect) and to close any applications still running, restart pc and try again. We've tried 'control, alt, delete' and closed anything running, and restarted the pc and tried again, but the same thing happens. Can anyone help??