When companies deploy Windows 7 most of them are looking at the 64-bit version of Windows 7. This architecture of Windows does not support running 16-bit applications, which unfortunately still is widely in use. If you do an inventory with ACT (Application Compatibility Toolkit) it will inventory all executables as well as CMD files and some other stuff and it will contain information about 16-bit applications lying around and being used by the users in your business.
The trick is that the GUI does not provide a way to view these applications so you have to turn to doing a SQL query using for instance the SQL Management Studio Express tools. Use the SQL Query below to get information on any none 32- or 64-bit executable. The query (thanks to Chris Jackson) will return for instance WOW (Windows on Windows) or DOS applications and that will/might indicate a 16-bit app which you should prioritize to test and handle as necessary.
SELECT DISTINCT Applications.appName, Static_App_Properties.fileName, fileModuleType
INNER JOIN Application_Instance_Files
ON Static_App_Properties.identity_hash = Application_Instance_Files.filePropertyID
INNER JOIN Applications
ON Application_Instance_Files.appID = Applications.identity_hash
WHERE fileModuleType<>'32BIT' AND fileModuleType<>'64BIT' AND propertyType='File'
ORDER BY appName
Happy hunting for 16-bit applications! :)