How can i simulate users in Windows?

hi everyone. I start with this technology a couple of weeks ago. Rigth now I download the OpenFire Server for Windows, and I ’ m trying to probe the scalability of the Server so I need to simulate concurrent users. Is a tool for that? I know that you can do with Tsung, but if I understand properly, that tool is for Linux, so I need one that can run over Windows.

Thanks a lot.

Matias