Install updates remotely

I need to create a script that checks a number of remote machines:

1. sees if there are Windows updates to apply, and if so
2. shuts down processes
3. shuts down database servers
4. installs all the Windows updates
5. restarts the machine

then when the machine comes back up, restarts all the databases and
processes.

Can anybody advise how I can go about writing a script that checks for the
presence of Windows updates and then installing them all?

At the moment I'm doing this manually once a week, but the number of servers
is increasing and so is the workload, and we need a semi-automatic solution
that takes the hard work out of this.

Thanks

Jay