That's kind of what I figured. C++ is too hard for my developers ;). Maybe I'll break out the C++ books and try something. It would be nice if MS included this in ISA. In Exchange 2000 SP1 it is a simple registry setting and automagically Outlook must be greater then version X.X to work. Most of my NIMDA problems would have been taken care of if my users had updated thier browsers and the fastest way to make them do that is take away their Internet untill they do. Using GPO and RIS would be OK if I was all 2000 ..maybe one day. I wonder about the PAC autoconfig script? If I could somehow determine the browser version there then I could redirect them to a page telling them to update. Brian