iMessage prompt on iMac start up Every time I turn my iMac desktop on, I'm prompted to sign into iMessage. That wasn't a big deal at first, but it's become a huge annoyance because I can't just click X to get rid of it, I have to go through 3 pages of prompts asking for a password, etc. Have tried to figure this out on my own, but I have been unsuccessful.
Launch iMessage, check Account info in Prefs.
Sign out &amp; back in again.
Reboot.

If you don't want iMessage on the desktop, then deactivate it with the first checkbox.