I'm not aware of a way to get the "used"/"last used" information, but that's not to say it can't be inventoried. If it exists in WMI, you can modify your SMS_DEF.MOF file to retrieve the values, as long as you know the appropriate Win32 WMI class. Even if it exists in the registry, you can still retrieve the value. To understand more on working with the SMS_DEF.MOF file, download the free MOF editing guide by Michael Schultz.
Also, check out Extended Software Inventory (ESI) for SMS. In addition to being able to inventory single files or groups of files with SMS, you can also get the last accessed information.
This was first published in May 2003