First, messenger service does not really have anything to do with
online live support. Newer Windows Operating systems do not come with
built in live chat support for websites, this is something that has to
be brought in from the outside.
The various different packages come with different setups, some
integrate fully, others are a seperate installation. I would look at
the system first to see if you like it, and not worry about
integration too much. All come with support and will work with the
proper training for your employees.
The best way for me to find software that would be a good fit for you
would be if you could show me examples of live chat integrated on
various website that you like. This would help me track down the right
software for you. In the meantime, I have selected some of my
favorites below, as well as some of the industry leaders (most have
demos available on their sites):
Live Person: http://www.liveperson.com (the best in my opinion)
Live Helper: http://www.livehelper.com
Bold Chat: http://www.boldchat.com
If none of the above meet your needs, please let me know and I will
continue to do my best to help you find a solution.
All the best,