Port 445: Effective/Safe Blocking

RE Original Question & Answer:

> Q:
> > When I do a netstat -an these ports are always listening, I
> > have a firewall blocking all lower ports but I was
> > wondering how I could close them all together, or what
> > programmes are using these ports?
> >
>
> I have a program (SafeXP) which "hardens" my win2k, and as
> part of this it shuts down port 445. However, when I tried
> to do a windows update I found that there was a problem with
> network connectivity, so backtracking I re-enabled port 445,
> and all went well. So, for some reason windows update needs
> this port, which is fine, now I open/shut the port as I need.
> No other program seems to complain about this.

A:
Actually, you can block 445 at the border and Windows Update runs fine.
I have blocked 135~139 and 445 with no ill effects on any of the
computers behind the routers/firewalls.

I suspect that your "hardening" breaks Windows Update.

soooo...
How do I Block port 445, disabling the messenger service, but not the utility? What exactly is meant by "the utility" vs. "the messenger service"? Can anyone explain the difference? Should I use Active Ports to accomplish this or should I use try to do it using WinXP commands somehow.

I am not networked (just a single host) with an internet connection. I do not file share, I have a single printer, and X number user accounts (one admin-type)--if any of this matters. (Many Thanks!)

Samwise