I received an email yesterday from an individual who had just installed the latest Windows Installer Platform SDK and had read a previous blog post that I wrote about using msi.chm for Windows Installer help information, but was unable to find msi.chm on his system. I took a look on our internal products server and couldn't find msi.chm there either, so I decided to go to the Platform SDK site and figure out what was going on. What I found is that I was basing the information in that blog entry about msi.chm on what appears to be an older version of the Platform SDK that I had downloaded a while ago and then just copied msi.chm off to a separate location.
I tried out a new download of the Windows Installer part of the Platform SDK, and it appears they have re-organized the help documentation for the entire SDK. Instead of having standalone CHM files for each product in the SDK, there is now a unified Platform SDK help collection and each individual product plugs in and registers an HXS (compiled help) file.
So what I had to do was launch the Platform SDK Documentation link on the Start menu after installation of the SDK. From there I was able to use the index and search that I normally use in my old copy of msi.chm, and as an added bonus there are updated topics for Windows Installer 3.0 and some of the incorrect info in my old version of msi.chm have been fixed.
Sorry for any confusion I created in my original post....