This is one question that gets asked around many times! The article “Exchange Server 2007: Platforms, Editions and Versions” gives important information to identify the build numbers for each Rollup Updates, however, it is unclear where to look for this information.

To solve that problem, I have come up with a script which looks at Exsetup.exe version and registry entries for each Rollup Update installed…

Uh, what happened to the rest of this post?

Well, since I wrote a better script that handles both Exchange 2010 and Exchange 2007, I have removed this script. You can find new version here.