Mend,

That is really interesting, because when I test my user agent string, I get

Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 2.0.50727; .NET CLR 1.1.4322; .NET CLR 3.0.04506.30)

However I do believe you because I searched around and I did find sources from Microsoft stating what you said.

So I am not sure why my PC (which is XP SP2) would not have this SV1 in the user agent.