How do I turn off massage service popups

Are these web browser popups or window system error message popups?

It window message notification service

If you're getting spam messages then block port 135 on your firewall.

If that's not an option there was a small free utility program on mcdev.com called nomess that would turn it off. The site is not responding so I've attached it. I've scanned it and I'm sure the system here will scan it but scan it just the same. (usual disclaimer) I'm pretty sure that this is what I used when I had problems...

Good Luck.

Edit: Check out this URL: CIACTech03-001: Spamming using the Windows Messenger Service