installers: installing the right version of VSTO 2005 runtime

[Tom Whittaker]

I created an Outlook plug-in that requires the VSTO 2005 runtime.

Right now, I'm checking if the "update" value under the following
Windows registry key is >= 1.

HKEY_LOCAL_MACHINE\Software\Microsoft\vsto runtime Setup\v2.0.50727

The problem is that I'm finding customer installations that do not
have an "update" value, an so I'm assuming this is the first version
of VSTO2005 runtime.

Question: Should the VSTO2005 runtime upgrades automatically upgrade
the current version of VSTO2005 runtime?

Question: Am I right in assuming that because there is no "update"
value that the installed version is the first version and not a
subsequent update?