The only information I've been able to find on this error is from
Josh Poley's MSDN blog.（這篇msdn上的文章已經不存在）
1190 0x800704A6 A system shutdown has already been scheduled. ERROR_SHUTDOWN_IS_SCHEDULED
However, the message implies that you get this when trying to schedule a shutdown. The only thing I can think of is that an installation/Windows update is waiting for a reboot.
You say that you can't see updates in Add/Remove programs - have you checked the "Show updates" option is checked?
Other posts that mention this error are similar in nature to yours.
