David,
I've been running MSE now for maybe two months? It is very unobtrusive and
doesn't seem to cause any problems on Vista Ultimate 64. I would hope not
since it is from MS. I subscribe to another list populated by PC world
former editors, and one of the authors of the "Windows Inside and Out"
series and a bunch of other very savvy computer people. Most of the people
on that list have also tried it and have had no ill effects nor infections.
There was some discussion about the high ratings of MSE coming mostly from
MS but I did replace Avast which I never had any trouble or cooties with for
many years with MSE. So far so good. 
There are apparently some issues if one has "Widows Update" turned off with
MSE not updating, but there is a MS utility to take care of that as well.
I'll dig up the URL if you need it.

Brad Loomis
San Miguel, CA

-----Original Message-----

Subject: [PCBUILD] Microsoft Security Essentials

  This new utility is available from

http://www.microsoft.com/security_essentials/

It's not clear how it stacks up against third party antivirus 
and anti-malware packages.  I only heard about it almost by 
accident.

  So far, it hasn't found anything to object to on any of my 
machines.  Nor does it seem to have trouble coexisting with my 
other protections despite the usual "uninstall all other" 
warnings.
  I'd be interested to hear of any negative experiences with it 
before I start sending my non-technical friends to go get it.

David Gillett

              The NOSPIN Group is now offering Free PC Tech
                     support at our newest website:
                          http://freepctech.com