While you can use ActiveX quite effectively to do this, I'd ask you to reconsider writing it in C#. With ActiveX in C#, you maybe requiring the end user to download the .NET framework to run on their machine in order to run your control.
Potentially, another approach may be to use an HTA (HTML Application) and a JavaScript query hitting the WMI services. You can find details on WMI
here[
^].