Finding the update rollup version you have installed on your Exchange 2010 boxes seems like a simple task. It is, if you know where to look for! There are a number of questions posted in Exchange forums where admins get confused with what they get from console/shell. The common places were an admin will look for displays only the major version numbers, like 2010 RTM, SP1 etc, and not the update rollups.
First place to look to find the build number for various update rollups is this Technet Wiki page. If you are running the latest rollup, the build number should be 14.1.339.1. Now, how do you find this number in your Exchange box?
If you have only a couple of Exchange 2010 servers, easiest is to go to Control Panel –> Programs and Features –> View Installed Updates.
Another option is to navigate to the Bin directory and select the properties of “Exsetup”.
The File version in the “Details” tab gives you the build number.
Yet another option is to open up Exchange Console and click on “Help” menu –> About Exchange Server 2010.
This brings a small window, which gives you the build number.
Run (Get-Command Exsetup).FileVersionInfo from Exchange Shell to find the build number easily.
This is good, if you only have a couple of servers. But, what if you are in a large environment and want to get this info? There are a number of PowerShell scripts which does the job. Check this script as an example.