How to uniquely identify a computer program?

Question

I have a more general question but any advice in implementing this in C# will also be very much appreciated. I am making a PC windows based program in C# and the idea is, for this program to send a small amount of data to a database located on a server somewhere, when the computer on which the program is running is connected to the internet. The PC program will be used by many people, but I would like to be able to know, which user (which program) sent the data. So, I would put one program out there for people to download and install. This program would then send some data (which depend on what the user does in the program) to a central database and I would like to know which of the programs out there sent the data. This way I could see what functionality of the program is used the most, do some people mostly use one functionality or more of them,...

The question therefore is, how to make one program but be able to distinguish the different "instances" of that program?

Does anyone have any ideas how to achieve this?

Thank you in advance for all of your answers. Cheers!

p.s.: I should mention that I am just starting to learn PC programming so try to make the answers simple to understand also for a beginner. :)

Answer 1

I'd create a GUID on the client and store it in settings somewhere, then send that with each message.

This can be stored in per user or global settings on the computer so you get user-based or computer-based fidelity.

This has the advantage that you are not storing any personal data, so won't run afoul of privacy laws.

Answer 2

You can use a combination of the MAC address and logged in user name (possibly hashed so you don't end up holding private information) to uniquely identify machine/user combinations.