installer.  This will permit the installation tool to remove
all running instances before attempting to remove the .exe.

Note that since the introduction of CriticalSections, our
compatibility with NT 4 was destroyed, and at this point that
is no loss (there are no more security updates to NT 4 ergo
it's not an OS we want connected to the internet, anyways).
The WTS api calls require 2000 or later, but I'm not wrapping
them since nobody notices the same issue with CriticalSections.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@603238 13f79535-47bb-0310-9956-ffa450edef68