NIS Live Update messes up my desktop

About a week ago I ran live update on my NIS software on my Windows 7 PC on which I have been using it for years.  As is often the case, it required a system restart, so I did it.  After the restart my desktop was all messed up.  Icons were gone, I couldn't even find them in my desktop folder.  My personalized background image was gone.  All in all the system was nowhere close to configured how it had been.  Fortunately I was able to do a system restore to a point a few weeks prior and while it wasn't perfect, it was close enough that I could make things back to the way they had been without too much effort.  Now NIS is again prompting me to do a system restart to complete a live update.  Obviously I want to make sure my AV software is up to date so I want to do it, but not if doing so it messes up my system again by doing so.  Has anyone seen this and is there a solution ?