I am trying to track down which user is making what changes in an application say 'Application A'. through SQL server Profiler. In Profiler, I set up a trace and the user name of that 'Application A' just says NT AUTHORITY\SYSTEM and it doesnt give me an different user name which are making those changes. The ClientProcessID and SPID are also the same. I am thinking that application A uses the same account to make changes for all the users. 

Anyideas of how to seperate the user names?

thanks. your help is appreciated.