If you are using SQL Profiler and you want to know which workstation is using the db you should use the hostname column in sql profiler.
While this was relatively straight forward in SQL Server 2000, users of SQL Server 2005 may find that the hostname column is not displayed when running the SQL Profiler. By default, SQL Server 2005 is hiding this column (and others) and if you want to see it or filter by it, you should activly choose it.
In order to display the hostname column in SQL Server Profiler you should:
1) Open SQL Server Profiler: SQL Server Management Studio -> Tools –> SQL Server Profiler
2) Start a New Trace: File –> New Trace
3) Connect to your server.
4) Go to the “Events Selection” tab.
5) Check the “Show all columns” box
6) Scroll to the hostname column
7) Check the event you want to trace in the hostname column.
In order to filter the results, you can click “Column filters” and choose the hostname on the left panel. This will allow you to set a “Like” or “Not Like” filter in the right panel.