I've just added that, now how do I track who's changing the data?
5 different users login and I use a login (yes/no), is there a way to track GUID of the user's PC or a type of Session_id to Identify the user?
You could also consider capturing the network username, as someone has already had to provide their username and password to log on to the computer. If you create a table of users, with their login and name, you can reference their name by pulling their login from the above method. This is usually the method I prefer to use. It still allows control as to who can get into the dB and who can't (by maintaining the user table), but it's also user friendly as the user is not prompted for information that's already available to the dB.